<?xml version="1.0" encoding="utf-8"?>
<!--Generated by DFIN XBRL Instance Document - http://www.dfinsolutions.com/ - Version R3.0 - on 23-February-2021 [01:44:56] {AM}-->
<linkbase xmlns="http://www.xbrl.org/2003/linkbase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xlink="http://www.w3.org/1999/xlink" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:xbrldt="http://xbrl.org/2005/xbrldt">
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ConsolidatedBalanceSheets" roleURI="http://wwww.teradyne.com/role/ConsolidatedBalanceSheets" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ConsolidatedBalanceSheetsParenthetical" roleURI="http://wwww.teradyne.com/role/ConsolidatedBalanceSheetsParenthetical" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ConsolidatedStatementsOfOperations" roleURI="http://wwww.teradyne.com/role/ConsolidatedStatementsOfOperations" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ConsolidatedStatementsOfComprehensiveIncome" roleURI="http://wwww.teradyne.com/role/ConsolidatedStatementsOfComprehensiveIncome" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ConsolidatedStatementsOfComprehensiveIncomeParenthetical" roleURI="http://wwww.teradyne.com/role/ConsolidatedStatementsOfComprehensiveIncomeParenthetical" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ConsolidatedStatementsOfShareholdersEquity" roleURI="http://wwww.teradyne.com/role/ConsolidatedStatementsOfShareholdersEquity" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ConsolidatedStatementsOfShareholdersEquityParenthetical" roleURI="http://wwww.teradyne.com/role/ConsolidatedStatementsOfShareholdersEquityParenthetical" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ConsolidatedStatementsOfCashFlows" roleURI="http://wwww.teradyne.com/role/ConsolidatedStatementsOfCashFlows" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#TheCompany" roleURI="http://wwww.teradyne.com/role/TheCompany" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#AccountingPolicies" roleURI="http://wwww.teradyne.com/role/AccountingPolicies" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#RecentlyIssuedAccountingPronouncements" roleURI="http://wwww.teradyne.com/role/RecentlyIssuedAccountingPronouncements" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#AcquisitionsAndInvestmentInOtherCompany" roleURI="http://wwww.teradyne.com/role/AcquisitionsAndInvestmentInOtherCompany" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#Inventories" roleURI="http://wwww.teradyne.com/role/Inventories" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#PropertyPlantAndEquipment" roleURI="http://wwww.teradyne.com/role/PropertyPlantAndEquipment" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#FinancialInstruments" roleURI="http://wwww.teradyne.com/role/FinancialInstruments" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#Leases" roleURI="http://wwww.teradyne.com/role/Leases" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#Debt" roleURI="http://wwww.teradyne.com/role/Debt" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#AccumulatedOtherComprehensiveLossIncome" roleURI="http://wwww.teradyne.com/role/AccumulatedOtherComprehensiveLossIncome" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#GoodwillAndIntangibleAssets" roleURI="http://wwww.teradyne.com/role/GoodwillAndIntangibleAssets" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#CommitmentsAndContingencies" roleURI="http://wwww.teradyne.com/role/CommitmentsAndContingencies" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#NetIncomePerCommonShare" roleURI="http://wwww.teradyne.com/role/NetIncomePerCommonShare" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#RetirementPlans" roleURI="http://wwww.teradyne.com/role/RetirementPlans" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#StockBasedCompensation" roleURI="http://wwww.teradyne.com/role/StockBasedCompensation" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#SavingsPlan" roleURI="http://wwww.teradyne.com/role/SavingsPlan" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#IncomeTaxes" roleURI="http://wwww.teradyne.com/role/IncomeTaxes" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#OperatingSegmentGeographicAndSignificantCustomerInformation" roleURI="http://wwww.teradyne.com/role/OperatingSegmentGeographicAndSignificantCustomerInformation" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#StockRepurchaseProgram" roleURI="http://wwww.teradyne.com/role/StockRepurchaseProgram" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#SubsequentEvents" roleURI="http://wwww.teradyne.com/role/SubsequentEvents" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#SupplementarydInformation" roleURI="http://wwww.teradyne.com/role/SupplementarydInformation" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ValuationAndQualifyingAccounts" roleURI="http://wwww.teradyne.com/role/ValuationAndQualifyingAccounts" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#AccountingPoliciesPolicies" roleURI="http://wwww.teradyne.com/role/AccountingPoliciesPolicies" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#AccountingPoliciesTables" roleURI="http://wwww.teradyne.com/role/AccountingPoliciesTables" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#AcquisitionsAndInvestmentInOtherCompanyTables" roleURI="http://wwww.teradyne.com/role/AcquisitionsAndInvestmentInOtherCompanyTables" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#InventoriesTables" roleURI="http://wwww.teradyne.com/role/InventoriesTables" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#PropertyPlantAndEquipmentTables" roleURI="http://wwww.teradyne.com/role/PropertyPlantAndEquipmentTables" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#FinancialInstrumentsTables" roleURI="http://wwww.teradyne.com/role/FinancialInstrumentsTables" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#LeasesTables" roleURI="http://wwww.teradyne.com/role/LeasesTables" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#DebtTables" roleURI="http://wwww.teradyne.com/role/DebtTables" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#AccumulatedOtherComprehensiveLossIncomeTables" roleURI="http://wwww.teradyne.com/role/AccumulatedOtherComprehensiveLossIncomeTables" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#GoodwillAndIntangibleAssetsTables" roleURI="http://wwww.teradyne.com/role/GoodwillAndIntangibleAssetsTables" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#NetIncomePerCommonShareTables" roleURI="http://wwww.teradyne.com/role/NetIncomePerCommonShareTables" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#RetirementPlansTables" roleURI="http://wwww.teradyne.com/role/RetirementPlansTables" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#StockBasedCompensationTables" roleURI="http://wwww.teradyne.com/role/StockBasedCompensationTables" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#IncomeTaxesTables" roleURI="http://wwww.teradyne.com/role/IncomeTaxesTables" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#OperatingSegmentGeographicAndSignificantCustomerInformationTables" roleURI="http://wwww.teradyne.com/role/OperatingSegmentGeographicAndSignificantCustomerInformationTables" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#SupplementaryInformationTables" roleURI="http://wwww.teradyne.com/role/SupplementaryInformationTables" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#TheCompanyAdditionalInformationDetail" roleURI="http://wwww.teradyne.com/role/TheCompanyAdditionalInformationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#AccountingPoliciesAdditionalInformationDetail" roleURI="http://wwww.teradyne.com/role/AccountingPoliciesAdditionalInformationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#DeferredRevenueAndCustomerAdvancesDetail" roleURI="http://wwww.teradyne.com/role/DeferredRevenueAndCustomerAdvancesDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#WarrantyAccrualIncludedInOtherAccruedLiabilitiesDetail" roleURI="http://wwww.teradyne.com/role/WarrantyAccrualIncludedInOtherAccruedLiabilitiesDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ExtendedProductWarrantyOfShortAndLongTermDeferredRevenueAndCustomerAdvancesDetail" roleURI="http://wwww.teradyne.com/role/ExtendedProductWarrantyOfShortAndLongTermDeferredRevenueAndCustomerAdvancesDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfPrepaymentsAndOtherCurrentAssetsDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfPrepaymentsAndOtherCurrentAssetsDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#UsefulLivesOfAssetsDetail" roleURI="http://wwww.teradyne.com/role/UsefulLivesOfAssetsDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#AcquisitionsAndInvestmentInOtherCompanyAdditionalInformationDetail" roleURI="http://wwww.teradyne.com/role/AcquisitionsAndInvestmentInOtherCompanyAdditionalInformationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#FinalAllocationOfPurchasePriceDetail" roleURI="http://wwww.teradyne.com/role/FinalAllocationOfPurchasePriceDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ComponentsOfIntangibleAssetsAndTheirEstimatedUsefulLivesAtAcquisitionDateDetail" roleURI="http://wwww.teradyne.com/role/ComponentsOfIntangibleAssetsAndTheirEstimatedUsefulLivesAtAcquisitionDateDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ProFormaResultsUnderAcquisitionDetail" roleURI="http://wwww.teradyne.com/role/ProFormaResultsUnderAcquisitionDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#RevenueAdditionalInformationDetail" roleURI="http://wwww.teradyne.com/role/RevenueAdditionalInformationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#DisaggregatedRevenueByPrimaryGeographicalMarketMajorProductLineAndTimingOfRevenueRecognitionDetail" roleURI="http://wwww.teradyne.com/role/DisaggregatedRevenueByPrimaryGeographicalMarketMajorProductLineAndTimingOfRevenueRecognitionDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#InventoriesAdditionalInformationDetail" roleURI="http://wwww.teradyne.com/role/InventoriesAdditionalInformationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#PropertyPlantAndEquipmentNetDetail" roleURI="http://wwww.teradyne.com/role/PropertyPlantAndEquipmentNetDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#PropertyPlantAndEquipmentAdditionalInformationDetail" roleURI="http://wwww.teradyne.com/role/PropertyPlantAndEquipmentAdditionalInformationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#FinancialInstrumentsAdditionalInformationDetail" roleURI="http://wwww.teradyne.com/role/FinancialInstrumentsAdditionalInformationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfFairValueOfFinancialAssetsAndLiabilitiesMeasuredOnRecurringBasisDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfFairValueOfFinancialAssetsAndLiabilitiesMeasuredOnRecurringBasisDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfReportedFinancialAssetsAndLiabilitiesDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfReportedFinancialAssetsAndLiabilitiesDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfChangesInFairValueOfLevel3ContingentConsiderationDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfChangesInFairValueOfLevel3ContingentConsiderationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfChangesInFairValueOfLevel3ContingentConsiderationParentheticalDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfChangesInFairValueOfLevel3ContingentConsiderationParentheticalDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#QuantitativeInformationAssociatedWithFairValueMeasurementOfLevel3FinancialInstrumentDetail" roleURI="http://wwww.teradyne.com/role/QuantitativeInformationAssociatedWithFairValueMeasurementOfLevel3FinancialInstrumentDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfCarryingAmountsAndFairValuesOfFinancialInstrumentsDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfCarryingAmountsAndFairValuesOfFinancialInstrumentsDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfAvailableForSaleMarketableSecuritiesDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfAvailableForSaleMarketableSecuritiesDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfReportedAvailableForSaleMarketableSecuritiesDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfReportedAvailableForSaleMarketableSecuritiesDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ContractualMaturitiesOfInvestmentsInDebtSecuritiesHeldDetail" roleURI="http://wwww.teradyne.com/role/ContractualMaturitiesOfInvestmentsInDebtSecuritiesHeldDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfNotionalAmountOfDerivativesDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfNotionalAmountOfDerivativesDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionAtFairValueDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionAtFairValueDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfEffectOfDerivativeInstrumentsInStatementOfOperationsRecognizedDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfEffectOfDerivativeInstrumentsInStatementOfOperationsRecognizedDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfEffectOfDerivativeInstrumentsInStatementOfOperationsRecognizedParentheticalDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfEffectOfDerivativeInstrumentsInStatementOfOperationsRecognizedParentheticalDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#LeasesAdditionalInformationDetail" roleURI="http://wwww.teradyne.com/role/LeasesAdditionalInformationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#SupplementalCashFlowInformationRelatedToLeasesDetail" roleURI="http://wwww.teradyne.com/role/SupplementalCashFlowInformationRelatedToLeasesDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfOperatingLeaseMaturityDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfOperatingLeaseMaturityDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#DebtAdditionalInformationDetail" roleURI="http://wwww.teradyne.com/role/DebtAdditionalInformationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ComponentsOfConvertibleSeniorNotesDetail" roleURI="http://wwww.teradyne.com/role/ComponentsOfConvertibleSeniorNotesDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#InterestExpenseOnConvertibleSeniorNotesDetail" roleURI="http://wwww.teradyne.com/role/InterestExpenseOnConvertibleSeniorNotesDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ChangesInAccumulatedOtherComprehensiveLossIncomeDetail" roleURI="http://wwww.teradyne.com/role/ChangesInAccumulatedOtherComprehensiveLossIncomeDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ChangesInAccumulatedOtherComprehensiveLossIncomeParentheticalDetail" roleURI="http://wwww.teradyne.com/role/ChangesInAccumulatedOtherComprehensiveLossIncomeParentheticalDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ReclassificationsOutOfAccumulatedOtherComprehensiveIncomeToStatementsOfOperationsDetail" roleURI="http://wwww.teradyne.com/role/ReclassificationsOutOfAccumulatedOtherComprehensiveIncomeToStatementsOfOperationsDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ReclassificationsOutOfAccumulatedOtherComprehensiveIncomeToStatementsOfOperationsParentheticalDetail" roleURI="http://wwww.teradyne.com/role/ReclassificationsOutOfAccumulatedOtherComprehensiveIncomeToStatementsOfOperationsParentheticalDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#GoodwillAndIntangibleAssetsAdditionalInformationDetail" roleURI="http://wwww.teradyne.com/role/GoodwillAndIntangibleAssetsAdditionalInformationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ChangesInCarryingAmountOfGoodwillBySegmentDetail" roleURI="http://wwww.teradyne.com/role/ChangesInCarryingAmountOfGoodwillBySegmentDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfAmortizableIntangibleAssetsDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfAmortizableIntangibleAssetsDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfAmortizableIntangibleAssetsParentheticalDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfAmortizableIntangibleAssetsParentheticalDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfEstimatedIntangibleAssetAmortizationExpenseDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfEstimatedIntangibleAssetAmortizationExpenseDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#CommitmentsAndContingenciesAdditionalInformationDetail" roleURI="http://wwww.teradyne.com/role/CommitmentsAndContingenciesAdditionalInformationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ComputationOfBasicAndDilutedNetIncomePerCommonShareDetail" roleURI="http://wwww.teradyne.com/role/ComputationOfBasicAndDilutedNetIncomePerCommonShareDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ComputationOfBasicAndDilutedNetIncomePerCommonShareParentheticalDetail" roleURI="http://wwww.teradyne.com/role/ComputationOfBasicAndDilutedNetIncomePerCommonShareParentheticalDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#NetIncomePerCommonShareAdditionalInformationDetail" roleURI="http://wwww.teradyne.com/role/NetIncomePerCommonShareAdditionalInformationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#RestructuringAndOtherAdditionalInformationDetail" roleURI="http://wwww.teradyne.com/role/RestructuringAndOtherAdditionalInformationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#RetirementPlansAdditionalInformationDetail" roleURI="http://wwww.teradyne.com/role/RetirementPlansAdditionalInformationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfDefinedBenefitPensionAndPostretirementBenefitPlanAssetsAndObligationDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfDefinedBenefitPensionAndPostretirementBenefitPlanAssetsAndObligationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfAmountsRecordedWithinStatementsOfFinancialPositionDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfAmountsRecordedWithinStatementsOfFinancialPositionDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfAmountsRecognizedInAccumulatedOtherComprehensiveIncomeDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfAmountsRecognizedInAccumulatedOtherComprehensiveIncomeDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfPensionPlansWithAccumulatedBenefitObligationAndProjectedBenefitObligationInExcessOfPlanAssetsDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfPensionPlansWithAccumulatedBenefitObligationAndProjectedBenefitObligationInExcessOfPlanAssetsDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfNetPeriodicPensionAndPostretirementIncomeCostDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfNetPeriodicPensionAndPostretirementIncomeCostDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfWeightedAverageAssumptionsToDetermineNetPeriodicPensionCostDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfWeightedAverageAssumptionsToDetermineNetPeriodicPensionCostDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfWeightedAverageAssumptionsToDeterminePensionObligationsDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfWeightedAverageAssumptionsToDeterminePensionObligationsDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfWeightedAveragePensionAssetsAllocationsByCategoryDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfWeightedAveragePensionAssetsAllocationsByCategoryDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfTargetAssetsAllocationDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfTargetAssetsAllocationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfFairValueOfPensionsPlanAssetsByAssetCategoryDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfFairValueOfPensionsPlanAssetsByAssetCategoryDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfExpectedFutureBenefitPaymentsDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfExpectedFutureBenefitPaymentsDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#StockBasedCompensationAdditionalInformationDetail" roleURI="http://wwww.teradyne.com/role/StockBasedCompensationAdditionalInformationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfEstimatedFairValueOfTsrPerformanceBasedRestrictedStockUnitAwardsAssumptionsDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfEstimatedFairValueOfTsrPerformanceBasedRestrictedStockUnitAwardsAssumptionsDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfEstimatedFairValueOfStockOptionsGrantUsingBlackScholesOptionPricingModelDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfEstimatedFairValueOfStockOptionsGrantUsingBlackScholesOptionPricingModelDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfStockCompensationPlanActivityDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfStockCompensationPlanActivityDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfShareBasedCompensationTotalSharesAvailableDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfShareBasedCompensationTotalSharesAvailableDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfWeightedAverageRestrictedStockUnitAwardFairValueDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfWeightedAverageRestrictedStockUnitAwardFairValueDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfRestrictedStockUnitAwardsAggregateIntrinsicValueDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfRestrictedStockUnitAwardsAggregateIntrinsicValueDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfRestrictedStockUnitsWeightedAverageRemainingContractualTermsDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfRestrictedStockUnitsWeightedAverageRemainingContractualTermsDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfWeightedAverageStockOptionsExercisePriceDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfWeightedAverageStockOptionsExercisePriceDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfStockOptionAggregatedIntrinsicValueInformationDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfStockOptionAggregatedIntrinsicValueInformationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfStockOptionsWeightedAverageRemainingContractualTermsDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfStockOptionsWeightedAverageRemainingContractualTermsDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#StockBasedCompensationDetail" roleURI="http://wwww.teradyne.com/role/StockBasedCompensationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#SavingsPlanAdditionalInformationDetail" roleURI="http://wwww.teradyne.com/role/SavingsPlanAdditionalInformationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfIncomeLossBeforeIncomeTaxesDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfIncomeLossBeforeIncomeTaxesDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfProvisionBenefitForIncomeTaxesFromOperationsDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfProvisionBenefitForIncomeTaxesFromOperationsDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#IncomeTaxesAdditionalInformationDetail" roleURI="http://wwww.teradyne.com/role/IncomeTaxesAdditionalInformationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfReconciliationOfEffectiveTaxRateDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfReconciliationOfEffectiveTaxRateDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfComponentsOfDeferredTaxAssetsLiabilitiesDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfComponentsOfDeferredTaxAssetsLiabilitiesDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#SummaryOfOperatingLossCarryforwardsDetail" roleURI="http://wwww.teradyne.com/role/SummaryOfOperatingLossCarryforwardsDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfUnrecognizedTaxBenefitsDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfUnrecognizedTaxBenefitsDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#OperatingSegmentGeographicAndSignificantCustomerInformationAdditionalInformationDetail" roleURI="http://wwww.teradyne.com/role/OperatingSegmentGeographicAndSignificantCustomerInformationAdditionalInformationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfSegmentInformationDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfSegmentInformationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfSegmentReportingInformationBySegmentChargesDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfSegmentReportingInformationBySegmentChargesDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfRevenuesByCountryDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfRevenuesByCountryDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfLongLivedAssetsByGeographicAreaDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfLongLivedAssetsByGeographicAreaDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ScheduleOfLongLivedAssetsByGeographicAreaParentheticalDetail" roleURI="http://wwww.teradyne.com/role/ScheduleOfLongLivedAssetsByGeographicAreaParentheticalDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#StockRepurchaseProgramAdditionalInformationDetail" roleURI="http://wwww.teradyne.com/role/StockRepurchaseProgramAdditionalInformationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#SubsequentEventsAdditionalInformationDetail" roleURI="http://wwww.teradyne.com/role/SubsequentEventsAdditionalInformationDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ConsolidatedQuarterlyStatementsOfOperationsDetail" roleURI="http://wwww.teradyne.com/role/ConsolidatedQuarterlyStatementsOfOperationsDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ConsolidatedQuarterlyStatementsOfOperationsParentheticalDetail" roleURI="http://wwww.teradyne.com/role/ConsolidatedQuarterlyStatementsOfOperationsParentheticalDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#ValuationAndQualifyingAccountsDetail" roleURI="http://wwww.teradyne.com/role/ValuationAndQualifyingAccountsDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#CoverPage" roleURI="http://wwww.teradyne.com/role/CoverPage" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#RestructuringAndOther" roleURI="http://wwww.teradyne.com/role/RestructuringAndOther" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#CompositionOfInventoriesNetDetail" roleURI="http://wwww.teradyne.com/role/CompositionOfInventoriesNetDetail" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#Revenue" roleURI="http://wwww.teradyne.com/role/Revenue" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#RevenueTables" roleURI="http://wwww.teradyne.com/role/RevenueTables" />
<roleRef xlink:type="simple" xlink:href="ter-20201231.xsd#DisaggregatedRevenueByPrimaryGeographicalMarketMajorProductLineAndTimingOfRevenueRecognitionParentheticalDetail" roleURI="http://wwww.teradyne.com/role/DisaggregatedRevenueByPrimaryGeographicalMarketMajorProductLineAndTimingOfRevenueRecognitionParentheticalDetail" />
<arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" />
<arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" />
<arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" />
<arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" />
<arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" />
<arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/notAll" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#notAll" />
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ConsolidatedBalanceSheets">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_32" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AssetsAbstract" xlink:label="loc_us-gaap_AssetsAbstract_27" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_32" xlink:to="loc_us-gaap_AssetsAbstract_27" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Assets" xlink:label="loc_us-gaap_Assets_42" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_27" xlink:to="loc_us-gaap_Assets_42" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="loc_us-gaap_AssetsCurrentAbstract_28" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_27" xlink:to="loc_us-gaap_AssetsCurrentAbstract_28" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_45" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_28" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_45" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesCurrent" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesCurrent_44" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_28" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesCurrent_44" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="loc_us-gaap_AssetsCurrent_48" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_28" xlink:to="loc_us-gaap_AssetsCurrent_48" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryNet" xlink:label="loc_us-gaap_InventoryNet_46" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_28" xlink:to="loc_us-gaap_InventoryNet_46" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_47" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_28" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_47" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_43" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_28" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_43" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesNoncurrent" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesNoncurrent_36" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_27" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesNoncurrent_36" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredIncomeTaxAssetsNet" xlink:label="loc_us-gaap_DeferredIncomeTaxAssetsNet_37" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_27" xlink:to="loc_us-gaap_DeferredIncomeTaxAssetsNet_37" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_40" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_27" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_40" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_39" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_27" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_39" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_35" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_27" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_35" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent" xlink:label="loc_us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent_38" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_27" xlink:to="loc_us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent_38" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_41" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_27" xlink:to="loc_us-gaap_Goodwill_41" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_396366" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_27" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_396366" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_66" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_32" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_66" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LiabilitiesAbstract" xlink:label="loc_us-gaap_LiabilitiesAbstract_30" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_32" xlink:to="loc_us-gaap_LiabilitiesAbstract_30" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccruedIncomeTaxesNoncurrent" xlink:label="loc_us-gaap_AccruedIncomeTaxesNoncurrent_55" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_30" xlink:to="loc_us-gaap_AccruedIncomeTaxesNoncurrent_55" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract_31" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_30" xlink:to="loc_us-gaap_LiabilitiesCurrentAbstract_31" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccruedIncomeTaxesCurrent" xlink:label="loc_us-gaap_AccruedIncomeTaxesCurrent_63" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_31" xlink:to="loc_us-gaap_AccruedIncomeTaxesCurrent_63" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="loc_us-gaap_LiabilitiesCurrent_64" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_31" xlink:to="loc_us-gaap_LiabilitiesCurrent_64" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherAccruedLiabilitiesCurrent" xlink:label="loc_us-gaap_OtherAccruedLiabilitiesCurrent_61" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_31" xlink:to="loc_us-gaap_OtherAccruedLiabilitiesCurrent_61" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="loc_us-gaap_AccountsPayableCurrent_58" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_31" xlink:to="loc_us-gaap_AccountsPayableCurrent_58" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DeferredRevenueAndCustomerAdvancesCurrent" xlink:label="loc_ter_DeferredRevenueAndCustomerAdvancesCurrent_60" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_31" xlink:to="loc_ter_DeferredRevenueAndCustomerAdvancesCurrent_60" use="optional" order="26" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiabilityCurrent" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityCurrent_62" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_31" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityCurrent_62" use="optional" order="27" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseLiabilityCurrent" xlink:label="loc_us-gaap_OperatingLeaseLiabilityCurrent_396367" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_31" xlink:to="loc_us-gaap_OperatingLeaseLiabilityCurrent_396367" use="optional" order="28" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:label="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_59" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_31" xlink:to="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_59" use="optional" order="29" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConvertibleDebtCurrent" xlink:label="loc_us-gaap_ConvertibleDebtCurrent_825796" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_31" xlink:to="loc_us-gaap_ConvertibleDebtCurrent_825796" use="optional" order="30" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConvertibleDebtNoncurrent" xlink:label="loc_us-gaap_ConvertibleDebtNoncurrent_56" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_30" xlink:to="loc_us-gaap_ConvertibleDebtNoncurrent_56" use="optional" order="31" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredRevenueNoncurrent" xlink:label="loc_us-gaap_DeferredRevenueNoncurrent_51" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_30" xlink:to="loc_us-gaap_DeferredRevenueNoncurrent_51" use="optional" order="32" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAndOtherLiabilitiesNoncurrent" xlink:label="loc_us-gaap_DeferredTaxAndOtherLiabilitiesNoncurrent_53" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_30" xlink:to="loc_us-gaap_DeferredTaxAndOtherLiabilitiesNoncurrent_53" use="optional" order="33" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Liabilities" xlink:label="loc_us-gaap_Liabilities_57" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_30" xlink:to="loc_us-gaap_Liabilities_57" use="optional" order="34" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:label="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_50" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_30" xlink:to="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_50" use="optional" order="35" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiabilityNoncurrent" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityNoncurrent_52" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_30" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityNoncurrent_52" use="optional" order="36" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_396369" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_30" xlink:to="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_396369" use="optional" order="37" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherAccruedLiabilitiesNoncurrent" xlink:label="loc_us-gaap_OtherAccruedLiabilitiesNoncurrent_54" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_30" xlink:to="loc_us-gaap_OtherAccruedLiabilitiesNoncurrent_54" use="optional" order="38" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_33" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_32" xlink:to="loc_us-gaap_StatementTable_33" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="39" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_29" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_33" xlink:to="loc_dei_LegalEntityAxis_29" use="optional" order="40" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_49" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_29" xlink:to="loc_dei_EntityDomain_49" use="optional" order="41" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_49_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_29" xlink:to="loc_dei_EntityDomain_49_default" use="optional" order="42" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="loc_us-gaap_CommitmentsAndContingencies_65" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_32" xlink:to="loc_us-gaap_CommitmentsAndContingencies_65" use="optional" order="43" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="loc_us-gaap_StockholdersEquityAbstract_34" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_32" xlink:to="loc_us-gaap_StockholdersEquityAbstract_34" use="optional" order="44" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_69" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_34" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_69" use="optional" order="45" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdditionalPaidInCapitalCommonStock" xlink:label="loc_us-gaap_AdditionalPaidInCapitalCommonStock_68" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_34" xlink:to="loc_us-gaap_AdditionalPaidInCapitalCommonStock_68" use="optional" order="46" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_71" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_34" xlink:to="loc_us-gaap_StockholdersEquity_71" use="optional" order="47" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockValue" xlink:label="loc_us-gaap_CommonStockValue_67" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_34" xlink:to="loc_us-gaap_CommonStockValue_67" use="optional" order="48" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_70" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_34" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_70" use="optional" order="49" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterestsAbstract" xlink:label="loc_us-gaap_TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterestsAbstract_825797" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_32" xlink:to="loc_us-gaap_TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterestsAbstract_825797" use="optional" order="50" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RedeemableNoncontrollingInterestEquityCommonCarryingAmount" xlink:label="loc_us-gaap_RedeemableNoncontrollingInterestEquityCommonCarryingAmount_825798" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterestsAbstract_825797" xlink:to="loc_us-gaap_RedeemableNoncontrollingInterestEquityCommonCarryingAmount_825798" use="optional" order="51" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ConsolidatedBalanceSheetsParenthetical">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_75" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_80" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_75" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_80" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_78" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_75" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_78" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:label="loc_us-gaap_CommonStockSharesIssued_81" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_75" xlink:to="loc_us-gaap_CommonStockSharesIssued_81" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_82" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_75" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_82" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_79" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_75" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_79" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_76" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_75" xlink:to="loc_us-gaap_StatementTable_76" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_74" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_76" xlink:to="loc_dei_LegalEntityAxis_74" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_77" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_74" xlink:to="loc_dei_EntityDomain_77" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_77_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_74" xlink:to="loc_dei_EntityDomain_77_default" use="optional" order="9" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ConsolidatedStatementsOfOperations">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_93" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CostOfRevenueAbstract" xlink:label="loc_us-gaap_CostOfRevenueAbstract_85" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93" xlink:to="loc_us-gaap_CostOfRevenueAbstract_85" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CostOfGoodsAndServicesSold" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_95" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfRevenueAbstract_85" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_95" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaap_OperatingIncomeLoss_113" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93" xlink:to="loc_us-gaap_OperatingIncomeLoss_113" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GrossProfit" xlink:label="loc_us-gaap_GrossProfit_112" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93" xlink:to="loc_us-gaap_GrossProfit_112" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingExpensesAbstract" xlink:label="loc_us-gaap_OperatingExpensesAbstract_88" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93" xlink:to="loc_us-gaap_OperatingExpensesAbstract_88" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_101" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_88" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_101" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingExpenses" xlink:label="loc_us-gaap_OperatingExpenses_105" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_88" xlink:to="loc_us-gaap_OperatingExpenses_105" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpense" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_99" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_88" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_99" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost_100" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_88" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost_100" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringSettlementAndImpairmentProvisions" xlink:label="loc_us-gaap_RestructuringSettlementAndImpairmentProvisions_102" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_88" xlink:to="loc_us-gaap_RestructuringSettlementAndImpairmentProvisions_102" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpenseAbstract" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_89" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_89" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestExpense" xlink:label="loc_us-gaap_InterestExpense_107" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_89" xlink:to="loc_us-gaap_InterestExpense_107" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentIncomeInterest" xlink:label="loc_us-gaap_InvestmentIncomeInterest_106" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_89" xlink:to="loc_us-gaap_InvestmentIncomeInterest_106" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_108" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_89" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_108" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="loc_us-gaap_EarningsPerShareAbstract_86" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93" xlink:to="loc_us-gaap_EarningsPerShareAbstract_86" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EarningsPerShareBasic" xlink:label="loc_us-gaap_EarningsPerShareBasic_96" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_86" xlink:to="loc_us-gaap_EarningsPerShareBasic_96" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="loc_us-gaap_EarningsPerShareDiluted_97" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_86" xlink:to="loc_us-gaap_EarningsPerShareDiluted_97" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_114" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_114" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_116" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93" xlink:to="loc_us-gaap_NetIncomeLoss_116" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_115" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_115" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenuesAbstract" xlink:label="loc_us-gaap_RevenuesAbstract_92" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93" xlink:to="loc_us-gaap_RevenuesAbstract_92" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Revenues" xlink:label="loc_us-gaap_Revenues_111" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_92" xlink:to="loc_us-gaap_Revenues_111" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_94" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_93" xlink:to="loc_us-gaap_StatementTable_94" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductOrServiceAxis" xlink:label="loc_srt_ProductOrServiceAxis_90" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_94" xlink:to="loc_srt_ProductOrServiceAxis_90" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_91" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_90" xlink:to="loc_srt_ProductsAndServicesDomain_91" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_91_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_90" xlink:to="loc_srt_ProductsAndServicesDomain_91_default" use="optional" order="26" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProductMember" xlink:label="loc_us-gaap_ProductMember_109" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_91" xlink:to="loc_us-gaap_ProductMember_109" use="optional" order="27" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ServiceMember" xlink:label="loc_us-gaap_ServiceMember_110" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_91" xlink:to="loc_us-gaap_ServiceMember_110" use="optional" order="28" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_87" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_94" xlink:to="loc_dei_LegalEntityAxis_87" use="optional" order="29" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_98" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_87" xlink:to="loc_dei_EntityDomain_98" use="optional" order="30" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_98_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_87" xlink:to="loc_dei_EntityDomain_98_default" use="optional" order="31" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_118" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_118" use="optional" order="32" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_117" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_117" use="optional" order="33" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ConsolidatedStatementsOfComprehensiveIncome">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_126" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_138" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_126" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTax_138" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_127" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_126" xlink:to="loc_us-gaap_StatementTable_127" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_122" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_127" xlink:to="loc_dei_LegalEntityAxis_122" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_128" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_122" xlink:to="loc_dei_EntityDomain_128" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_128_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_122" xlink:to="loc_dei_EntityDomain_128_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_137" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_126" xlink:to="loc_us-gaap_NetIncomeLoss_137" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract_125" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_126" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract_125" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_135" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract_125" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_135" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_136" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract_125" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_136" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParentAbstract" xlink:label="loc_us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParentAbstract_123" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract_125" xlink:to="loc_us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParentAbstract_123" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax_131" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParentAbstract_123" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax_131" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax_130" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParentAbstract_123" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax_130" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_129" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParentAbstract_123" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_129" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPeriodIncreaseDecreaseAbstract" xlink:label="loc_us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPeriodIncreaseDecreaseAbstract_124" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract_125" xlink:to="loc_us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPeriodIncreaseDecreaseAbstract_124" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax_132" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPeriodIncreaseDecreaseAbstract_124" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax_132" use="optional" order="15" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ConsolidatedStatementsOfComprehensiveIncomeParenthetical">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_142" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_143" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_142" xlink:to="loc_us-gaap_StatementTable_143" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_141" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_143" xlink:to="loc_dei_LegalEntityAxis_141" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_144" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_141" xlink:to="loc_dei_EntityDomain_144" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_144_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_141" xlink:to="loc_dei_EntityDomain_144_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax_396421" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_142" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax_396421" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax_396418" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_142" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax_396418" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax_396416" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_142" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax_396416" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax_396419" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_142" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax_396419" use="optional" order="8" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ConsolidatedStatementsOfShareholdersEquity">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_156" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DividendsCash" xlink:label="loc_us-gaap_DividendsCash_179" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_156" xlink:to="loc_us-gaap_DividendsCash_179" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalEquityComponentOfConvertibleDebt" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalEquityComponentOfConvertibleDebt_169" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_156" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalEquityComponentOfConvertibleDebt_169" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_157" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_156" xlink:to="loc_us-gaap_StatementTable_157" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_155" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_157" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_155" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_152" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_155" xlink:to="loc_us-gaap_EquityComponentDomain_152" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_152_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_155" xlink:to="loc_us-gaap_EquityComponentDomain_152_default" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaap_CommonStockMember_158" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_152" xlink:to="loc_us-gaap_CommonStockMember_158" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="loc_us-gaap_RetainedEarningsMember_161" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_152" xlink:to="loc_us-gaap_RetainedEarningsMember_161" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_159" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_152" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_159" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_160" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_152" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_160" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CumulativeEffectPeriodOfAdoptionAxis" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_819288" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_157" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_819288" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CumulativeEffectPeriodOfAdoptionDomain" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_819289" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_819288" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_819289" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CumulativeEffectPeriodOfAdoptionDomain" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_819289_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_819288" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_819289_default" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember_819290" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_819289" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember_819290" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_828985" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_157" xlink:to="loc_us-gaap_StatementClassOfStockAxis_828985" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_828986" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_828985" xlink:to="loc_us-gaap_ClassOfStockDomain_828986" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_828986_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_828985" xlink:to="loc_us-gaap_ClassOfStockDomain_828986_default" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConvertibleCommonStockMember" xlink:label="loc_us-gaap_ConvertibleCommonStockMember_825831" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_828986" xlink:to="loc_us-gaap_ConvertibleCommonStockMember_825831" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_165" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_156" xlink:to="loc_us-gaap_StockholdersEquity_165" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_180" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_156" xlink:to="loc_us-gaap_NetIncomeLoss_180" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_173" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_156" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_173" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharesIssued" xlink:label="loc_us-gaap_SharesIssued_166" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_156" xlink:to="loc_us-gaap_SharesIssued_166" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarnings" xlink:label="loc_ter_TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarnings_415264" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_156" xlink:to="loc_ter_TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarnings_415264" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_474536" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_156" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_474536" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SharesOfStockIssuedDuringPeriodShareBasedCompensationNetOfSharesWithheldForTaxes" xlink:label="loc_ter_SharesOfStockIssuedDuringPeriodShareBasedCompensationNetOfSharesWithheldForTaxes_498187" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_156" xlink:to="loc_ter_SharesOfStockIssuedDuringPeriodShareBasedCompensationNetOfSharesWithheldForTaxes_498187" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_StockIssuedDuringPeriodValueShareBasedCompensationNetOfSharesWithheldForTaxes" xlink:label="loc_ter_StockIssuedDuringPeriodValueShareBasedCompensationNetOfSharesWithheldForTaxes_498188" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_156" xlink:to="loc_ter_StockIssuedDuringPeriodValueShareBasedCompensationNetOfSharesWithheldForTaxes_498188" use="optional" order="26" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfEquitySecuritiesNetOfTax" xlink:label="loc_ter_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfEquitySecuritiesNetOfTax_321762" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_156" xlink:to="loc_ter_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfEquitySecuritiesNetOfTax_321762" use="optional" order="27" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodShares" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_175" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_156" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_175" use="optional" order="28" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodValue" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_174" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_156" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_174" use="optional" order="29" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_825827" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_156" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_825827" use="optional" order="30" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ConsolidatedStatementsOfShareholdersEquityParenthetical">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_190" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_191" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_190" xlink:to="loc_us-gaap_StatementTable_191" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_189" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_191" xlink:to="loc_dei_LegalEntityAxis_189" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_192" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_189" xlink:to="loc_dei_EntityDomain_192" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_192_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_189" xlink:to="loc_dei_EntityDomain_192_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_321763" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_191" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_321763" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_321764" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_321763" xlink:to="loc_us-gaap_EquityComponentDomain_321764" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_321764_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_321763" xlink:to="loc_us-gaap_EquityComponentDomain_321764_default" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockDividendsPerShareCashPaid" xlink:label="loc_us-gaap_CommonStockDividendsPerShareCashPaid_420873" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_190" xlink:to="loc_us-gaap_CommonStockDividendsPerShareCashPaid_420873" use="optional" order="8" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ConsolidatedStatementsOfCashFlows">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_208" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_256" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_208" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_256" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents" xlink:label="loc_us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents_254" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_208" xlink:to="loc_us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents_254" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_206" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_208" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_206" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_251" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_206" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_251" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromContributionInAidOfConstruction" xlink:label="loc_us-gaap_ProceedsFromContributionInAidOfConstruction_245" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_206" xlink:to="loc_us-gaap_ProceedsFromContributionInAidOfConstruction_245" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsForProceedsFromLifeInsurancePolicies" xlink:label="loc_us-gaap_PaymentsForProceedsFromLifeInsurancePolicies_249" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_206" xlink:to="loc_us-gaap_PaymentsForProceedsFromLifeInsurancePolicies_249" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities" xlink:label="loc_us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities_248" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_206" xlink:to="loc_us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities_248" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities" xlink:label="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_247" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_206" xlink:to="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_247" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsToAcquireAvailableForSaleSecurities" xlink:label="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecurities_246" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_206" xlink:to="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecurities_246" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_244" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_206" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_244" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_677347" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_206" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_677347" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_207" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_208" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_207" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_201" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_207" xlink:to="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_201" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdjustmentForAmortization" xlink:label="loc_us-gaap_AdjustmentForAmortization_212" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_201" xlink:to="loc_us-gaap_AdjustmentForAmortization_212" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_216" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_201" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_216" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Depreciation" xlink:label="loc_us-gaap_Depreciation_211" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_201" xlink:to="loc_us-gaap_Depreciation_211" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_218" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_201" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_218" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherNoncashIncomeExpense" xlink:label="loc_us-gaap_OtherNoncashIncomeExpense_223" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_201" xlink:to="loc_us-gaap_OtherNoncashIncomeExpense_223" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_214" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_201" xlink:to="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_214" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_203" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_201" xlink:to="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_203" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayableAndOtherOperatingLiabilities" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayableAndOtherOperatingLiabilities_229" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_203" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayableAndOtherOperatingLiabilities_229" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_226" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_203" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_226" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInContractWithCustomerLiability" xlink:label="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_230" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_203" xlink:to="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_230" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInInventories" xlink:label="loc_us-gaap_IncreaseDecreaseInInventories_227" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_203" xlink:to="loc_us-gaap_IncreaseDecreaseInInventories_227" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInPensionAndPostretirementObligations" xlink:label="loc_us-gaap_IncreaseDecreaseInPensionAndPostretirementObligations_231" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_203" xlink:to="loc_us-gaap_IncreaseDecreaseInPensionAndPostretirementObligations_231" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInIncomeTaxes" xlink:label="loc_us-gaap_IncreaseDecreaseInIncomeTaxes_232" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_203" xlink:to="loc_us-gaap_IncreaseDecreaseInIncomeTaxes_232" use="optional" order="26" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_228" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_203" xlink:to="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_228" use="optional" order="27" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GainLossOnSaleOfInvestments" xlink:label="loc_us-gaap_GainLossOnSaleOfInvestments_217" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_201" xlink:to="loc_us-gaap_GainLossOnSaleOfInvestments_217" use="optional" order="28" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryWriteDown" xlink:label="loc_us-gaap_InventoryWriteDown_215" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_201" xlink:to="loc_us-gaap_InventoryWriteDown_215" use="optional" order="29" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="loc_us-gaap_ShareBasedCompensation_213" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_201" xlink:to="loc_us-gaap_ShareBasedCompensation_213" use="optional" order="30" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment" xlink:label="loc_us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment_817381" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_201" xlink:to="loc_us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment_817381" use="optional" order="31" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_253" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_207" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_253" use="optional" order="32" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_us-gaap_ProfitLoss_252" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_207" xlink:to="loc_us-gaap_ProfitLoss_252" use="optional" order="33" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_205" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_208" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_205" use="optional" order="34" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities" xlink:label="loc_us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities_238" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_205" xlink:to="loc_us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities_238" use="optional" order="35" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_243" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_205" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_243" use="optional" order="36" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_235" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_205" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_235" use="optional" order="37" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsOfDividends" xlink:label="loc_us-gaap_PaymentsOfDividends_236" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_205" xlink:to="loc_us-gaap_PaymentsOfDividends_236" use="optional" order="38" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions_234" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_205" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions_234" use="optional" order="39" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation" xlink:label="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_237" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_205" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_237" use="optional" order="40" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_255" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_208" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_255" use="optional" order="41" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_209" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_208" xlink:to="loc_us-gaap_StatementTable_209" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="42" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_204" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_209" xlink:to="loc_dei_LegalEntityAxis_204" use="optional" order="43" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_233" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_204" xlink:to="loc_dei_EntityDomain_233" use="optional" order="44" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_233_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_204" xlink:to="loc_dei_EntityDomain_233_default" use="optional" order="45" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SupplementalCashFlowInformationAbstract" xlink:label="loc_us-gaap_SupplementalCashFlowInformationAbstract_210" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_208" xlink:to="loc_us-gaap_SupplementalCashFlowInformationAbstract_210" use="optional" order="46" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:label="loc_us-gaap_NoncashInvestingAndFinancingItemsAbstract_720378" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract_210" xlink:to="loc_us-gaap_NoncashInvestingAndFinancingItemsAbstract_720378" use="optional" order="47" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:label="loc_us-gaap_CapitalExpendituresIncurredButNotYetPaid_720382" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoncashInvestingAndFinancingItemsAbstract_720378" xlink:to="loc_us-gaap_CapitalExpendituresIncurredButNotYetPaid_720382" use="optional" order="48" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_CashPaidDuringPeriodForAbstract" xlink:label="loc_ter_CashPaidDuringPeriodForAbstract_817442" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract_210" xlink:to="loc_ter_CashPaidDuringPeriodForAbstract_817442" use="optional" order="49" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestPaidNet" xlink:label="loc_us-gaap_InterestPaidNet_817450" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_CashPaidDuringPeriodForAbstract_817442" xlink:to="loc_us-gaap_InterestPaidNet_817450" use="optional" order="50" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxesPaidNet" xlink:label="loc_us-gaap_IncomeTaxesPaidNet_817451" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_CashPaidDuringPeriodForAbstract_817442" xlink:to="loc_us-gaap_IncomeTaxesPaidNet_817451" use="optional" order="51" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/TheCompany">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2079" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NatureOfOperations" xlink:label="loc_us-gaap_NatureOfOperations_2082" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2079" xlink:to="loc_us-gaap_NatureOfOperations_2082" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2080" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2079" xlink:to="loc_us-gaap_StatementTable_2080" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2078" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2080" xlink:to="loc_dei_LegalEntityAxis_2078" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2081" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2078" xlink:to="loc_dei_EntityDomain_2081" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2081_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2078" xlink:to="loc_dei_EntityDomain_2081_default" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/AccountingPolicies">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2086" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2087" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2086" xlink:to="loc_us-gaap_StatementTable_2087" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2085" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2087" xlink:to="loc_dei_LegalEntityAxis_2085" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2088" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2085" xlink:to="loc_dei_EntityDomain_2088" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2088_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2085" xlink:to="loc_dei_EntityDomain_2088_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SignificantAccountingPoliciesTextBlock" xlink:label="loc_us-gaap_SignificantAccountingPoliciesTextBlock_2089" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2086" xlink:to="loc_us-gaap_SignificantAccountingPoliciesTextBlock_2089" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/RecentlyIssuedAccountingPronouncements">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2135" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DescriptionOfNewAccountingPronouncementsNotYetAdopted" xlink:label="loc_us-gaap_DescriptionOfNewAccountingPronouncementsNotYetAdopted_2138" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2135" xlink:to="loc_us-gaap_DescriptionOfNewAccountingPronouncementsNotYetAdopted_2138" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2136" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2135" xlink:to="loc_us-gaap_StatementTable_2136" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2134" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2136" xlink:to="loc_dei_LegalEntityAxis_2134" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2137" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2134" xlink:to="loc_dei_EntityDomain_2137" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2137_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2134" xlink:to="loc_dei_EntityDomain_2137_default" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/AcquisitionsAndInvestmentInOtherCompany">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2142" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2143" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2142" xlink:to="loc_us-gaap_StatementTable_2143" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2141" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2143" xlink:to="loc_dei_LegalEntityAxis_2141" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2144" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2141" xlink:to="loc_dei_EntityDomain_2144" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2144_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2141" xlink:to="loc_dei_EntityDomain_2144_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationDisclosureTextBlock" xlink:label="loc_us-gaap_BusinessCombinationDisclosureTextBlock_2145" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2142" xlink:to="loc_us-gaap_BusinessCombinationDisclosureTextBlock_2145" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/Inventories">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2161" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryDisclosureTextBlock" xlink:label="loc_us-gaap_InventoryDisclosureTextBlock_2164" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2161" xlink:to="loc_us-gaap_InventoryDisclosureTextBlock_2164" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2162" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2161" xlink:to="loc_us-gaap_StatementTable_2162" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2160" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2162" xlink:to="loc_dei_LegalEntityAxis_2160" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2163" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2160" xlink:to="loc_dei_EntityDomain_2163" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2163_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2160" xlink:to="loc_dei_EntityDomain_2163_default" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/PropertyPlantAndEquipment">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2175" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock_2178" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2175" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock_2178" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2176" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2175" xlink:to="loc_us-gaap_StatementTable_2176" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2174" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2176" xlink:to="loc_dei_LegalEntityAxis_2174" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2177" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2174" xlink:to="loc_dei_EntityDomain_2177" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2177_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2174" xlink:to="loc_dei_EntityDomain_2177_default" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/FinancialInstruments">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2189" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2190" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2189" xlink:to="loc_us-gaap_StatementTable_2190" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2188" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2190" xlink:to="loc_dei_LegalEntityAxis_2188" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2191" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2188" xlink:to="loc_dei_EntityDomain_2191" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2191_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2188" xlink:to="loc_dei_EntityDomain_2191_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueDisclosuresTextBlock" xlink:label="loc_us-gaap_FairValueDisclosuresTextBlock_2192" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2189" xlink:to="loc_us-gaap_FairValueDisclosuresTextBlock_2192" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/Leases">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_396650" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_396647" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_396650" xlink:to="loc_us-gaap_StatementTable_396647" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_396648" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_396647" xlink:to="loc_us-gaap_StatementClassOfStockAxis_396648" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_396649" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_396648" xlink:to="loc_us-gaap_ClassOfStockDomain_396649" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_396649_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_396648" xlink:to="loc_us-gaap_ClassOfStockDomain_396649_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeasesOfLesseeDisclosureTextBlock" xlink:label="loc_us-gaap_OperatingLeasesOfLesseeDisclosureTextBlock_396651" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_396650" xlink:to="loc_us-gaap_OperatingLeasesOfLesseeDisclosureTextBlock_396651" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/Debt">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2211" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2212" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2211" xlink:to="loc_us-gaap_StatementTable_2212" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2210" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2212" xlink:to="loc_dei_LegalEntityAxis_2210" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2213" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2210" xlink:to="loc_dei_EntityDomain_2213" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2213_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2210" xlink:to="loc_dei_EntityDomain_2213_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtDisclosureTextBlock" xlink:label="loc_us-gaap_DebtDisclosureTextBlock_2214" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2211" xlink:to="loc_us-gaap_DebtDisclosureTextBlock_2214" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/AccumulatedOtherComprehensiveLossIncome">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2225" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2226" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2225" xlink:to="loc_us-gaap_StatementTable_2226" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2224" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2226" xlink:to="loc_dei_LegalEntityAxis_2224" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2227" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2224" xlink:to="loc_dei_EntityDomain_2227" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2227_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2224" xlink:to="loc_dei_EntityDomain_2227_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ComprehensiveIncomeNoteTextBlock" xlink:label="loc_us-gaap_ComprehensiveIncomeNoteTextBlock_2228" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2225" xlink:to="loc_us-gaap_ComprehensiveIncomeNoteTextBlock_2228" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/GoodwillAndIntangibleAssets">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2240" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock" xlink:label="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock_2243" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2240" xlink:to="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock_2243" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2241" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2240" xlink:to="loc_us-gaap_StatementTable_2241" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2239" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2241" xlink:to="loc_dei_LegalEntityAxis_2239" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2242" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2239" xlink:to="loc_dei_EntityDomain_2242" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2242_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2239" xlink:to="loc_dei_EntityDomain_2242_default" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/CommitmentsAndContingencies">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2259" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:label="loc_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_2262" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2259" xlink:to="loc_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_2262" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2260" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2259" xlink:to="loc_us-gaap_StatementTable_2260" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2258" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2260" xlink:to="loc_dei_LegalEntityAxis_2258" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2261" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2258" xlink:to="loc_dei_EntityDomain_2261" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2261_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2258" xlink:to="loc_dei_EntityDomain_2261_default" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/NetIncomePerCommonShare">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2273" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EarningsPerShareTextBlock" xlink:label="loc_us-gaap_EarningsPerShareTextBlock_2276" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2273" xlink:to="loc_us-gaap_EarningsPerShareTextBlock_2276" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2274" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2273" xlink:to="loc_us-gaap_StatementTable_2274" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2272" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2274" xlink:to="loc_dei_LegalEntityAxis_2272" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2275" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2272" xlink:to="loc_dei_EntityDomain_2275" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2275_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2272" xlink:to="loc_dei_EntityDomain_2275_default" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/RetirementPlans">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2296" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock" xlink:label="loc_us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock_2300" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2296" xlink:to="loc_us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock_2300" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2297" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2296" xlink:to="loc_us-gaap_StatementTable_2297" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2293" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2297" xlink:to="loc_dei_LegalEntityAxis_2293" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2298" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2293" xlink:to="loc_dei_EntityDomain_2298" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2298_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2293" xlink:to="loc_dei_EntityDomain_2298_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_2294" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2297" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_2294" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_2295" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_2294" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_2295" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_2295_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_2294" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_2295_default" use="optional" order="8" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/StockBasedCompensation">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2326" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_2329" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2326" xlink:to="loc_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_2329" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2327" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2326" xlink:to="loc_us-gaap_StatementTable_2327" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2325" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2327" xlink:to="loc_dei_LegalEntityAxis_2325" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2328" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2325" xlink:to="loc_dei_EntityDomain_2328" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2328_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2325" xlink:to="loc_dei_EntityDomain_2328_default" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/SavingsPlan">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2351" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DefinedContributionDisclosureTextBlock" xlink:label="loc_ter_DefinedContributionDisclosureTextBlock_2354" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2351" xlink:to="loc_ter_DefinedContributionDisclosureTextBlock_2354" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2352" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2351" xlink:to="loc_us-gaap_StatementTable_2352" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2350" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2352" xlink:to="loc_dei_LegalEntityAxis_2350" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2353" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2350" xlink:to="loc_dei_EntityDomain_2353" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2353_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2350" xlink:to="loc_dei_EntityDomain_2353_default" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/IncomeTaxes">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2358" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2359" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2358" xlink:to="loc_us-gaap_StatementTable_2359" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2357" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2359" xlink:to="loc_dei_LegalEntityAxis_2357" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2360" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2357" xlink:to="loc_dei_EntityDomain_2360" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2360_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2357" xlink:to="loc_dei_EntityDomain_2360_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxDisclosureTextBlock" xlink:label="loc_us-gaap_IncomeTaxDisclosureTextBlock_2361" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2358" xlink:to="loc_us-gaap_IncomeTaxDisclosureTextBlock_2361" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/OperatingSegmentGeographicAndSignificantCustomerInformation">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2376" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2377" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2376" xlink:to="loc_us-gaap_StatementTable_2377" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2375" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2377" xlink:to="loc_dei_LegalEntityAxis_2375" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2378" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2375" xlink:to="loc_dei_EntityDomain_2378" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2378_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2375" xlink:to="loc_dei_EntityDomain_2378_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentReportingDisclosureTextBlock" xlink:label="loc_us-gaap_SegmentReportingDisclosureTextBlock_2379" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2376" xlink:to="loc_us-gaap_SegmentReportingDisclosureTextBlock_2379" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/StockRepurchaseProgram">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2400" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2401" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2400" xlink:to="loc_us-gaap_StatementTable_2401" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2399" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2401" xlink:to="loc_dei_LegalEntityAxis_2399" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2402" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2399" xlink:to="loc_dei_EntityDomain_2402" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2402_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2399" xlink:to="loc_dei_EntityDomain_2402_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_StockRepurchaseProgramTextBlock" xlink:label="loc_ter_StockRepurchaseProgramTextBlock_2403" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2400" xlink:to="loc_ter_StockRepurchaseProgramTextBlock_2403" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/SubsequentEvents">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2407" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2408" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2407" xlink:to="loc_us-gaap_StatementTable_2408" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2406" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2408" xlink:to="loc_dei_LegalEntityAxis_2406" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2409" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2406" xlink:to="loc_dei_EntityDomain_2409" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2409_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2406" xlink:to="loc_dei_EntityDomain_2409_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventsTextBlock" xlink:label="loc_us-gaap_SubsequentEventsTextBlock_2410" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2407" xlink:to="loc_us-gaap_SubsequentEventsTextBlock_2410" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/SupplementarydInformation">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2414" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_QuarterlyFinancialInformationTextBlock" xlink:label="loc_us-gaap_QuarterlyFinancialInformationTextBlock_2417" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2414" xlink:to="loc_us-gaap_QuarterlyFinancialInformationTextBlock_2417" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2415" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2414" xlink:to="loc_us-gaap_StatementTable_2415" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2413" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2415" xlink:to="loc_dei_LegalEntityAxis_2413" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2416" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2413" xlink:to="loc_dei_EntityDomain_2416" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2416_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2413" xlink:to="loc_dei_EntityDomain_2416_default" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ValuationAndQualifyingAccounts">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2428" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2429" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2428" xlink:to="loc_us-gaap_StatementTable_2429" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2427" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2429" xlink:to="loc_dei_LegalEntityAxis_2427" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2430" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2427" xlink:to="loc_dei_EntityDomain_2430" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2430_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2427" xlink:to="loc_dei_EntityDomain_2430_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock" xlink:label="loc_srt_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock_2431" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2428" xlink:to="loc_srt_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock_2431" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/AccountingPoliciesPolicies">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2093" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdvertisingCostsPolicyTextBlock" xlink:label="loc_us-gaap_AdvertisingCostsPolicyTextBlock_2111" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_us-gaap_AdvertisingCostsPolicyTextBlock_2111" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ComprehensiveIncomePolicyPolicyTextBlock" xlink:label="loc_us-gaap_ComprehensiveIncomePolicyPolicyTextBlock_2114" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_us-gaap_ComprehensiveIncomePolicyPolicyTextBlock_2114" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_EngineeringAndDevelopmentCostsPolicyTextBlock" xlink:label="loc_ter_EngineeringAndDevelopmentCostsPolicyTextBlock_2108" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_ter_EngineeringAndDevelopmentCostsPolicyTextBlock_2108" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:label="loc_us-gaap_FairValueMeasurementPolicyPolicyTextBlock_2102" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_us-gaap_FairValueMeasurementPolicyPolicyTextBlock_2102" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_GoodwillIntangibleAndLongLivedAssetsPolicyTextBlock" xlink:label="loc_ter_GoodwillIntangibleAndLongLivedAssetsPolicyTextBlock_2106" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_ter_GoodwillIntangibleAndLongLivedAssetsPolicyTextBlock_2106" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxPolicyTextBlock" xlink:label="loc_us-gaap_IncomeTaxPolicyTextBlock_2110" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_us-gaap_IncomeTaxPolicyTextBlock_2110" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryPolicyTextBlock" xlink:label="loc_us-gaap_InventoryPolicyTextBlock_2100" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_us-gaap_InventoryPolicyTextBlock_2100" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRecognitionPolicyTextBlock" xlink:label="loc_us-gaap_RevenueRecognitionPolicyTextBlock_2097" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_us-gaap_RevenueRecognitionPolicyTextBlock_2097" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StandardProductWarrantyPolicy" xlink:label="loc_us-gaap_StandardProductWarrantyPolicy_2098" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_us-gaap_StandardProductWarrantyPolicy_2098" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2094" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_us-gaap_StatementTable_2094" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2092" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2094" xlink:to="loc_dei_LegalEntityAxis_2092" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2095" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2092" xlink:to="loc_dei_EntityDomain_2095" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2095_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2092" xlink:to="loc_dei_EntityDomain_2095_default" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_StockCompensationPlansAndEmployeeStockPurchasePlanPolicyTextBlock" xlink:label="loc_ter_StockCompensationPlansAndEmployeeStockPurchasePlanPolicyTextBlock_2109" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_ter_StockCompensationPlansAndEmployeeStockPurchasePlanPolicyTextBlock_2109" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock" xlink:label="loc_us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock_2112" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock_2112" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionAndOtherPostretirementPlansPolicy" xlink:label="loc_us-gaap_PensionAndOtherPostretirementPlansPolicy_2104" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_us-gaap_PensionAndOtherPostretirementPlansPolicy_2104" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PostemploymentBenefitPlansPolicy" xlink:label="loc_us-gaap_PostemploymentBenefitPlansPolicy_2105" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_us-gaap_PostemploymentBenefitPlansPolicy_2105" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_PrepaidExpensesPolicyTextBlock" xlink:label="loc_ter_PrepaidExpensesPolicyTextBlock_2103" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_ter_PrepaidExpensesPolicyTextBlock_2103" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_PreparationOfFinancialStatementsAndUseOfEstimatesPolicyTextBlock" xlink:label="loc_ter_PreparationOfFinancialStatementsAndUseOfEstimatesPolicyTextBlock_2096" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_ter_PreparationOfFinancialStatementsAndUseOfEstimatesPolicyTextBlock_2096" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EarningsPerSharePolicyTextBlock" xlink:label="loc_us-gaap_EarningsPerSharePolicyTextBlock_2113" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_us-gaap_EarningsPerSharePolicyTextBlock_2113" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_2107" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_2107" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TradeAndOtherAccountsReceivablePolicy" xlink:label="loc_us-gaap_TradeAndOtherAccountsReceivablePolicy_2099" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_us-gaap_TradeAndOtherAccountsReceivablePolicy_2099" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:label="loc_us-gaap_BasisOfAccountingPolicyPolicyTextBlock_396453" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_us-gaap_BasisOfAccountingPolicyPolicyTextBlock_396453" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeLeasesPolicyTextBlock" xlink:label="loc_us-gaap_LesseeLeasesPolicyTextBlock_396459" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_us-gaap_LesseeLeasesPolicyTextBlock_396459" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CostMethodInvestmentsPolicy" xlink:label="loc_us-gaap_CostMethodInvestmentsPolicy_813400" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_us-gaap_CostMethodInvestmentsPolicy_813400" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationsPolicy" xlink:label="loc_us-gaap_BusinessCombinationsPolicy_813404" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2093" xlink:to="loc_us-gaap_BusinessCombinationsPolicy_813404" use="optional" order="26" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/AccountingPoliciesTables">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2119" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ScheduleOfExtendedProductWarrantyLiabilityTableTextBlock" xlink:label="loc_ter_ScheduleOfExtendedProductWarrantyLiabilityTableTextBlock_2128" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2119" xlink:to="loc_ter_ScheduleOfExtendedProductWarrantyLiabilityTableTextBlock_2128" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ScheduleOfDeferredRevenueAndCustomerAdvancesTableTextBlock" xlink:label="loc_ter_ScheduleOfDeferredRevenueAndCustomerAdvancesTableTextBlock_2126" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2119" xlink:to="loc_ter_ScheduleOfDeferredRevenueAndCustomerAdvancesTableTextBlock_2126" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_PrepaidExpenseAndOtherAssetsTableTextBlock" xlink:label="loc_ter_PrepaidExpenseAndOtherAssetsTableTextBlock_2129" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2119" xlink:to="loc_ter_PrepaidExpenseAndOtherAssetsTableTextBlock_2129" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTextBlock_2130" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2119" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTextBlock_2130" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2120" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2119" xlink:to="loc_us-gaap_StatementTable_2120" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_2117" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2120" xlink:to="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_2117" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_2121" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_2117" xlink:to="loc_us-gaap_TypeOfAdoptionMember_2121" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_2121_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_2117" xlink:to="loc_us-gaap_TypeOfAdoptionMember_2121_default" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2118" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2120" xlink:to="loc_dei_LegalEntityAxis_2118" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2122" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2118" xlink:to="loc_dei_EntityDomain_2122" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2122_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2118" xlink:to="loc_dei_EntityDomain_2122_default" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfProductWarrantyLiabilityTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfProductWarrantyLiabilityTableTextBlock_2127" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2119" xlink:to="loc_us-gaap_ScheduleOfProductWarrantyLiabilityTableTextBlock_2127" use="optional" order="12" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/AcquisitionsAndInvestmentInOtherCompanyTables">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2151" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionProFormaInformationTextBlock" xlink:label="loc_us-gaap_BusinessAcquisitionProFormaInformationTextBlock_2157" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2151" xlink:to="loc_us-gaap_BusinessAcquisitionProFormaInformationTextBlock_2157" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock_2156" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2151" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock_2156" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock_2155" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2151" xlink:to="loc_us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock_2155" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2152" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2151" xlink:to="loc_us-gaap_StatementTable_2152" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_2149" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2152" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_2149" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2148" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_2149" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2148" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2148_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_2149" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2148_default" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_MobileIndustrialRobotsApsMember" xlink:label="loc_ter_MobileIndustrialRobotsApsMember_2153" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2148" xlink:to="loc_ter_MobileIndustrialRobotsApsMember_2153" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_AutoguideLlcMember" xlink:label="loc_ter_AutoguideLlcMember_813409" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2148" xlink:to="loc_ter_AutoguideLlcMember_813409" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2150" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2152" xlink:to="loc_dei_LegalEntityAxis_2150" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2154" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2150" xlink:to="loc_dei_EntityDomain_2154" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2154_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2150" xlink:to="loc_dei_EntityDomain_2154_default" use="optional" order="12" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/InventoriesTables">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2168" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2169" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2168" xlink:to="loc_us-gaap_StatementTable_2169" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2167" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2169" xlink:to="loc_dei_LegalEntityAxis_2167" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2170" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2167" xlink:to="loc_dei_EntityDomain_2170" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2170_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2167" xlink:to="loc_dei_EntityDomain_2170_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfInventoryCurrentTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfInventoryCurrentTableTextBlock_2171" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2168" xlink:to="loc_us-gaap_ScheduleOfInventoryCurrentTableTextBlock_2171" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/PropertyPlantAndEquipmentTables">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2182" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2183" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2182" xlink:to="loc_us-gaap_StatementTable_2183" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2181" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2183" xlink:to="loc_dei_LegalEntityAxis_2181" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2184" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2181" xlink:to="loc_dei_EntityDomain_2184" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2184_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2181" xlink:to="loc_dei_EntityDomain_2184_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ScheduleOfPropertyPlantAndEquipmentTableTextBlock" xlink:label="loc_ter_ScheduleOfPropertyPlantAndEquipmentTableTextBlock_2185" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2182" xlink:to="loc_ter_ScheduleOfPropertyPlantAndEquipmentTableTextBlock_2185" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/FinancialInstrumentsTables">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2196" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDerivativeInstrumentsGainLossInStatementOfFinancialPerformanceTextBlock" xlink:label="loc_us-gaap_ScheduleOfDerivativeInstrumentsGainLossInStatementOfFinancialPerformanceTextBlock_2207" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2196" xlink:to="loc_us-gaap_ScheduleOfDerivativeInstrumentsGainLossInStatementOfFinancialPerformanceTextBlock_2207" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock" xlink:label="loc_us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock_2206" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2196" xlink:to="loc_us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock_2206" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock_2199" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2196" xlink:to="loc_us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock_2199" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfNotionalAmountsOfOutstandingDerivativePositionsTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfNotionalAmountsOfOutstandingDerivativePositionsTableTextBlock_2205" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2196" xlink:to="loc_us-gaap_ScheduleOfNotionalAmountsOfOutstandingDerivativePositionsTableTextBlock_2205" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2197" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2196" xlink:to="loc_us-gaap_StatementTable_2197" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2195" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2197" xlink:to="loc_dei_LegalEntityAxis_2195" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2198" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2195" xlink:to="loc_dei_EntityDomain_2198" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2198_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2195" xlink:to="loc_dei_EntityDomain_2198_default" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesTextBlock" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesTextBlock_2204" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2196" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesTextBlock_2204" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock_2201" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2196" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock_2201" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock_2203" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2196" xlink:to="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock_2203" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ScheduleOfCarryingAmountsAndFairValuesOfFinancialInstrumentsTableTextBlock" xlink:label="loc_ter_ScheduleOfCarryingAmountsAndFairValuesOfFinancialInstrumentsTableTextBlock_2202" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2196" xlink:to="loc_ter_ScheduleOfCarryingAmountsAndFairValuesOfFinancialInstrumentsTableTextBlock_2202" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock_2200" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2196" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock_2200" use="optional" order="13" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/LeasesTables">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_396658" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_396655" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_396658" xlink:to="loc_us-gaap_StatementTable_396655" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock_396661" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_396658" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock_396661" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ScheduleOfCashFlowInformationOfOperatingLeasesTableTextBlock" xlink:label="loc_ter_ScheduleOfCashFlowInformationOfOperatingLeasesTableTextBlock_396659" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_396658" xlink:to="loc_ter_ScheduleOfCashFlowInformationOfOperatingLeasesTableTextBlock_396659" use="optional" order="3" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/DebtTables">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2218" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConvertibleDebtTableTextBlock" xlink:label="loc_us-gaap_ConvertibleDebtTableTextBlock_2221" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2218" xlink:to="loc_us-gaap_ConvertibleDebtTableTextBlock_2221" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2219" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2218" xlink:to="loc_us-gaap_StatementTable_2219" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2217" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2219" xlink:to="loc_dei_LegalEntityAxis_2217" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2220" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2217" xlink:to="loc_dei_EntityDomain_2220" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2220_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2217" xlink:to="loc_dei_EntityDomain_2220_default" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/AccumulatedOtherComprehensiveLossIncomeTables">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2232" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTableTextBlock" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTableTextBlock_2236" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2232" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTableTextBlock_2236" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2233" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2232" xlink:to="loc_us-gaap_StatementTable_2233" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2231" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2233" xlink:to="loc_dei_LegalEntityAxis_2231" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2234" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2231" xlink:to="loc_dei_EntityDomain_2234" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2234_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2231" xlink:to="loc_dei_EntityDomain_2234_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock_2235" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2232" xlink:to="loc_us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock_2235" use="optional" order="6" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/GoodwillAndIntangibleAssetsTables">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2249" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfGoodwillTextBlock" xlink:label="loc_us-gaap_ScheduleOfGoodwillTextBlock_2253" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2249" xlink:to="loc_us-gaap_ScheduleOfGoodwillTextBlock_2253" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2250" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2249" xlink:to="loc_us-gaap_StatementTable_2250" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2246" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2250" xlink:to="loc_dei_LegalEntityAxis_2246" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2251" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2246" xlink:to="loc_dei_EntityDomain_2251" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2251_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2246" xlink:to="loc_dei_EntityDomain_2251_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_2248" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2250" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_2248" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_2247" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_2248" xlink:to="loc_us-gaap_SegmentDomain_2247" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_2247_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_2248" xlink:to="loc_us-gaap_SegmentDomain_2247_default" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_WirelessTestMember" xlink:label="loc_ter_WirelessTestMember_2252" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_2247" xlink:to="loc_ter_WirelessTestMember_2252" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:label="loc_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock_2255" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2249" xlink:to="loc_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock_2255" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock_2254" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2249" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock_2254" use="optional" order="11" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/NetIncomePerCommonShareTables">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2280" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_2283" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2280" xlink:to="loc_us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_2283" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2281" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2280" xlink:to="loc_us-gaap_StatementTable_2281" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2279" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2281" xlink:to="loc_dei_LegalEntityAxis_2279" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2282" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2279" xlink:to="loc_dei_EntityDomain_2282" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2282_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2279" xlink:to="loc_dei_EntityDomain_2282_default" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/RetirementPlansTables">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2306" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfAmountsInAccumulatedOtherComprehensiveIncomeLossToBeRecognizedOverNextFiscalYearTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfAmountsInAccumulatedOtherComprehensiveIncomeLossToBeRecognizedOverNextFiscalYearTableTextBlock_2314" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2306" xlink:to="loc_us-gaap_ScheduleOfAmountsInAccumulatedOtherComprehensiveIncomeLossToBeRecognizedOverNextFiscalYearTableTextBlock_2314" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfAmountsRecognizedInBalanceSheetTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfAmountsRecognizedInBalanceSheetTableTextBlock_2313" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2306" xlink:to="loc_us-gaap_ScheduleOfAmountsRecognizedInBalanceSheetTableTextBlock_2313" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2307" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2306" xlink:to="loc_us-gaap_StatementTable_2307" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2303" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2307" xlink:to="loc_dei_LegalEntityAxis_2303" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2308" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2303" xlink:to="loc_dei_EntityDomain_2308" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2308_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2303" xlink:to="loc_dei_EntityDomain_2308_default" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_2304" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2307" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_2304" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_2305" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_2304" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_2305" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_2305_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_2304" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_2305_default" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_2311" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_2305" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_2311" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock_2321" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2306" xlink:to="loc_us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock_2321" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfChangesInProjectedBenefitObligationsTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfChangesInProjectedBenefitObligationsTableTextBlock_2312" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2306" xlink:to="loc_us-gaap_ScheduleOfChangesInProjectedBenefitObligationsTableTextBlock_2312" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfNetBenefitCostsTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfNetBenefitCostsTableTextBlock_2316" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2306" xlink:to="loc_us-gaap_ScheduleOfNetBenefitCostsTableTextBlock_2316" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfAllocationOfPlanAssetsTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfAllocationOfPlanAssetsTableTextBlock_2319" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2306" xlink:to="loc_us-gaap_ScheduleOfAllocationOfPlanAssetsTableTextBlock_2319" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfAssumptionsUsedTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfAssumptionsUsedTableTextBlock_2317" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2306" xlink:to="loc_us-gaap_ScheduleOfAssumptionsUsedTableTextBlock_2317" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ScheduleOfWeightedAveragePensionAssetAllocationsByCategoryTableTextBlock" xlink:label="loc_ter_ScheduleOfWeightedAveragePensionAssetAllocationsByCategoryTableTextBlock_2318" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2306" xlink:to="loc_ter_ScheduleOfWeightedAveragePensionAssetAllocationsByCategoryTableTextBlock_2318" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfEffectOfSignificantUnobservableInputsChangesInPlanAssetsTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfEffectOfSignificantUnobservableInputsChangesInPlanAssetsTableTextBlock_2320" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2306" xlink:to="loc_us-gaap_ScheduleOfEffectOfSignificantUnobservableInputsChangesInPlanAssetsTableTextBlock_2320" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfAccumulatedBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfAccumulatedBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock_2315" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2306" xlink:to="loc_us-gaap_ScheduleOfAccumulatedBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock_2315" use="optional" order="18" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/StockBasedCompensationTables">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2333" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ScheduleOfShareBasedPaymentAwardTotalShareholderReturnPlanValuationAssumptionsTableTextBlock" xlink:label="loc_ter_ScheduleOfShareBasedPaymentAwardTotalShareholderReturnPlanValuationAssumptionsTableTextBlock_2336" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2333" xlink:to="loc_ter_ScheduleOfShareBasedPaymentAwardTotalShareholderReturnPlanValuationAssumptionsTableTextBlock_2336" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ScheduleOfWeightedAverageStockOptionsExercisePriceTableTextBlock" xlink:label="loc_ter_ScheduleOfWeightedAverageStockOptionsExercisePriceTableTextBlock_2343" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2333" xlink:to="loc_ter_ScheduleOfWeightedAverageStockOptionsExercisePriceTableTextBlock_2343" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2334" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2333" xlink:to="loc_us-gaap_StatementTable_2334" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2332" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2334" xlink:to="loc_dei_LegalEntityAxis_2332" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2335" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2332" xlink:to="loc_dei_EntityDomain_2335" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2335_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2332" xlink:to="loc_dei_EntityDomain_2335_default" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfOtherShareBasedCompensationActivityTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfOtherShareBasedCompensationActivityTableTextBlock_2347" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2333" xlink:to="loc_us-gaap_ScheduleOfOtherShareBasedCompensationActivityTableTextBlock_2347" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock_2338" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2333" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock_2338" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAggregateIntrinsicValueTableTextBlock" xlink:label="loc_ter_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAggregateIntrinsicValueTableTextBlock_2344" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2333" xlink:to="loc_ter_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAggregateIntrinsicValueTableTextBlock_2344" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageContractualTermsTableTextBlock" xlink:label="loc_ter_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageContractualTermsTableTextBlock_2345" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2333" xlink:to="loc_ter_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageContractualTermsTableTextBlock_2345" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock_2340" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2333" xlink:to="loc_us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock_2340" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock_2341" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2333" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock_2341" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock_2337" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2333" xlink:to="loc_us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock_2337" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockUnitsVestedAndExpectedToVestTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockUnitsVestedAndExpectedToVestTableTextBlock_2342" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2333" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockUnitsVestedAndExpectedToVestTableTextBlock_2342" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardTotalSharesAvailableTableTextBlock" xlink:label="loc_ter_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardTotalSharesAvailableTableTextBlock_2339" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2333" xlink:to="loc_ter_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardTotalSharesAvailableTableTextBlock_2339" use="optional" order="15" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/IncomeTaxesTables">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2365" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_2370" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2365" xlink:to="loc_us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_2370" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_2369" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2365" xlink:to="loc_us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_2369" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock_2368" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2365" xlink:to="loc_us-gaap_ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock_2368" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2366" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2365" xlink:to="loc_us-gaap_StatementTable_2366" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2364" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2366" xlink:to="loc_dei_LegalEntityAxis_2364" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2367" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2364" xlink:to="loc_dei_EntityDomain_2367" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2367_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2364" xlink:to="loc_dei_EntityDomain_2367_default" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SummaryOfIncomeTaxContingenciesTextBlock" xlink:label="loc_us-gaap_SummaryOfIncomeTaxContingenciesTextBlock_2372" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2365" xlink:to="loc_us-gaap_SummaryOfIncomeTaxContingenciesTextBlock_2372" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SummaryOfOperatingLossCarryforwardsTextBlock" xlink:label="loc_us-gaap_SummaryOfOperatingLossCarryforwardsTextBlock_2371" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2365" xlink:to="loc_us-gaap_SummaryOfOperatingLossCarryforwardsTextBlock_2371" use="optional" order="9" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/OperatingSegmentGeographicAndSignificantCustomerInformationTables">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2385" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfRevenueFromExternalCustomersAttributedToForeignCountriesByGeographicAreaTextBlock" xlink:label="loc_us-gaap_ScheduleOfRevenueFromExternalCustomersAttributedToForeignCountriesByGeographicAreaTextBlock_2395" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2385" xlink:to="loc_us-gaap_ScheduleOfRevenueFromExternalCustomersAttributedToForeignCountriesByGeographicAreaTextBlock_2395" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsByGeographicalAreasTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsByGeographicalAreasTableTextBlock_2396" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2385" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsByGeographicalAreasTableTextBlock_2396" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ScheduleOfSegmentReportingInformationBySegmentChargesTableTextBlock" xlink:label="loc_ter_ScheduleOfSegmentReportingInformationBySegmentChargesTableTextBlock_2394" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2385" xlink:to="loc_ter_ScheduleOfSegmentReportingInformationBySegmentChargesTableTextBlock_2394" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock_2393" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2385" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock_2393" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2386" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2385" xlink:to="loc_us-gaap_StatementTable_2386" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2382" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2386" xlink:to="loc_dei_LegalEntityAxis_2382" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2387" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2382" xlink:to="loc_dei_EntityDomain_2387" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2387_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2382" xlink:to="loc_dei_EntityDomain_2387_default" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_2384" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2386" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_2384" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_2383" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_2384" xlink:to="loc_us-gaap_SegmentDomain_2383" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_2383_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_2384" xlink:to="loc_us-gaap_SegmentDomain_2383_default" use="optional" order="11" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/SupplementaryInformationTables">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2421" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2422" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2421" xlink:to="loc_us-gaap_StatementTable_2422" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2420" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2422" xlink:to="loc_dei_LegalEntityAxis_2420" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2423" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2420" xlink:to="loc_dei_EntityDomain_2423" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2423_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2420" xlink:to="loc_dei_EntityDomain_2423_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock_2424" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2421" xlink:to="loc_us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock_2424" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/TheCompanyAdditionalInformationDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_262" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh_269" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_262" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh_269" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_272" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_262" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_272" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_RepaymentOfDebtDemanded" xlink:label="loc_ter_RepaymentOfDebtDemanded_817734" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_262" xlink:to="loc_ter_RepaymentOfDebtDemanded_817734" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_268" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_262" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_268" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_264" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_262" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_264" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_261" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_264" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_261" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_260" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_261" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_260" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_260_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_261" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_260_default" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_MobileIndustrialRobotsApsMember" xlink:label="loc_ter_MobileIndustrialRobotsApsMember_267" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_260" xlink:to="loc_ter_MobileIndustrialRobotsApsMember_267" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_EnergidTechnologiesCorporationMember" xlink:label="loc_ter_EnergidTechnologiesCorporationMember_817729" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_260" xlink:to="loc_ter_EnergidTechnologiesCorporationMember_817729" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_LemsysMember" xlink:label="loc_ter_LemsysMember_817730" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_260" xlink:to="loc_ter_LemsysMember_817730" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_AutoguideLlcMember" xlink:label="loc_ter_AutoguideLlcMember_817741" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_260" xlink:to="loc_ter_AutoguideLlcMember_817741" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_263" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_264" xlink:to="loc_dei_LegalEntityAxis_263" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_273" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_263" xlink:to="loc_dei_EntityDomain_273" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_273_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_263" xlink:to="loc_dei_EntityDomain_273_default" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_817735" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_264" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_817735" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_817736" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_817735" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_817736" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_817736_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_817735" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_817736_default" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_817742" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_264" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_817742" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_817743" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_817742" xlink:to="loc_us-gaap_RelatedPartyDomain_817743" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_817743_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_817742" xlink:to="loc_us-gaap_RelatedPartyDomain_817743_default" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_RealWarInMember" xlink:label="loc_ter_RealWarInMember_817744" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_817743" xlink:to="loc_ter_RealWarInMember_817744" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_817745" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_264" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_817745" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_817746" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_817745" xlink:to="loc_us-gaap_SegmentDomain_817746" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_817746_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_817745" xlink:to="loc_us-gaap_SegmentDomain_817746_default" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_IndustrialAutomationMember" xlink:label="loc_ter_IndustrialAutomationMember_817747" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_817746" xlink:to="loc_ter_IndustrialAutomationMember_817747" use="optional" order="26" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_817727" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_262" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_817727" use="optional" order="27" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityMethodInvestments" xlink:label="loc_us-gaap_EquityMethodInvestments_817733" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_262" xlink:to="loc_us-gaap_EquityMethodInvestments_817733" use="optional" order="28" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment" xlink:label="loc_us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment_817738" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_262" xlink:to="loc_us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment_817738" use="optional" order="29" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:label="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_817739" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_262" xlink:to="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_817739" use="optional" order="30" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_QuantityOfMaterialToBeTransported" xlink:label="loc_ter_QuantityOfMaterialToBeTransported_817748" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_262" xlink:to="loc_ter_QuantityOfMaterialToBeTransported_817748" use="optional" order="31" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/AccountingPoliciesAdditionalInformationDetail">
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SummaryOfSignificantAccountingPoliciesLineItems" xlink:label="loc_ter_SummaryOfSignificantAccountingPoliciesLineItems_280" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_BookValueOfInternallyManufacturedTestSystemsSold" xlink:label="loc_ter_BookValueOfInternallyManufacturedTestSystemsSold_293" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_SummaryOfSignificantAccountingPoliciesLineItems_280" xlink:to="loc_ter_BookValueOfInternallyManufacturedTestSystemsSold_293" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdvertisingExpense" xlink:label="loc_us-gaap_AdvertisingExpense_296" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_SummaryOfSignificantAccountingPoliciesLineItems_280" xlink:to="loc_us-gaap_AdvertisingExpense_296" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignCurrencyTransactionGainLossUnrealized" xlink:label="loc_us-gaap_ForeignCurrencyTransactionGainLossUnrealized_297" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_SummaryOfSignificantAccountingPoliciesLineItems_280" xlink:to="loc_us-gaap_ForeignCurrencyTransactionGainLossUnrealized_297" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DepreciationPeriodOverLifeToCostOfRevenuesAndSellingAndAdministrativeExpenses" xlink:label="loc_ter_DepreciationPeriodOverLifeToCostOfRevenuesAndSellingAndAdministrativeExpenses_292" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_SummaryOfSignificantAccountingPoliciesLineItems_280" xlink:to="loc_ter_DepreciationPeriodOverLifeToCostOfRevenuesAndSellingAndAdministrativeExpenses_292" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_StandardProductWarrantyPeriod" xlink:label="loc_ter_StandardProductWarrantyPeriod_289" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_SummaryOfSignificantAccountingPoliciesLineItems_280" xlink:to="loc_ter_StandardProductWarrantyPeriod_289" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SummaryOfSignificantAccountingPoliciesTable" xlink:label="loc_ter_SummaryOfSignificantAccountingPoliciesTable_281" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ter_SummaryOfSignificantAccountingPoliciesLineItems_280" xlink:to="loc_ter_SummaryOfSignificantAccountingPoliciesTable_281" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_278" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_SummaryOfSignificantAccountingPoliciesTable_281" xlink:to="loc_dei_LegalEntityAxis_278" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_285" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_278" xlink:to="loc_dei_EntityDomain_285" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_285_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_278" xlink:to="loc_dei_EntityDomain_285_default" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_396519" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_SummaryOfSignificantAccountingPoliciesTable_281" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_396519" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_396520" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_396519" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_396520" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_396520_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_396519" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_396520_default" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_276" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_SummaryOfSignificantAccountingPoliciesTable_281" xlink:to="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_276" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_282" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_276" xlink:to="loc_us-gaap_TypeOfAdoptionMember_282" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_282_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_276" xlink:to="loc_us-gaap_TypeOfAdoptionMember_282_default" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccountingStandardsUpdate201601Member" xlink:label="loc_us-gaap_AccountingStandardsUpdate201601Member_299" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfAdoptionMember_282" xlink:to="loc_us-gaap_AccountingStandardsUpdate201601Member_299" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_279" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_SummaryOfSignificantAccountingPoliciesTable_281" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_279" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_277" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_279" xlink:to="loc_us-gaap_EquityComponentDomain_277" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_277_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_279" xlink:to="loc_us-gaap_EquityComponentDomain_277_default" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="loc_us-gaap_RetainedEarningsMember_283" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_277" xlink:to="loc_us-gaap_RetainedEarningsMember_283" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_284" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_277" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_284" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_330018" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_SummaryOfSignificantAccountingPoliciesTable_281" xlink:to="loc_srt_RangeAxis_330018" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_330021" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_330018" xlink:to="loc_srt_RangeMember_330021" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_330021_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_330018" xlink:to="loc_srt_RangeMember_330021_default" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ContractWithCustomerDurationAxis" xlink:label="loc_us-gaap_ContractWithCustomerDurationAxis_329982" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_SummaryOfSignificantAccountingPoliciesTable_281" xlink:to="loc_us-gaap_ContractWithCustomerDurationAxis_329982" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ContractWithCustomerDurationDomain" xlink:label="loc_us-gaap_ContractWithCustomerDurationDomain_329983" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ContractWithCustomerDurationAxis_329982" xlink:to="loc_us-gaap_ContractWithCustomerDurationDomain_329983" use="optional" order="26" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ContractWithCustomerDurationDomain" xlink:label="loc_us-gaap_ContractWithCustomerDurationDomain_329983_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ContractWithCustomerDurationAxis_329982" xlink:to="loc_us-gaap_ContractWithCustomerDurationDomain_329983_default" use="optional" order="27" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccountsAndNotesReceivableNet" xlink:label="loc_us-gaap_AccountsAndNotesReceivableNet_321743" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_SummaryOfSignificantAccountingPoliciesLineItems_280" xlink:to="loc_us-gaap_AccountsAndNotesReceivableNet_321743" use="optional" order="28" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_813640" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_SummaryOfSignificantAccountingPoliciesLineItems_280" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_813640" use="optional" order="29" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/DeferredRevenueAndCustomerAdvancesDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredRevenueArrangementLineItems" xlink:label="loc_us-gaap_DeferredRevenueArrangementLineItems_394" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DeferredRevenueAndCustomerAdvances" xlink:label="loc_ter_DeferredRevenueAndCustomerAdvances_399" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DeferredRevenueArrangementLineItems_394" xlink:to="loc_ter_DeferredRevenueAndCustomerAdvances_399" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DeferredRevenueAndCustomerAdvancesMaintenanceServiceAndTraining" xlink:label="loc_ter_DeferredRevenueAndCustomerAdvancesMaintenanceServiceAndTraining_396" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DeferredRevenueArrangementLineItems_394" xlink:to="loc_ter_DeferredRevenueAndCustomerAdvancesMaintenanceServiceAndTraining_396" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DeferredRevenueAndCustomerAdvancesUndeliveredElementsAndOther" xlink:label="loc_ter_DeferredRevenueAndCustomerAdvancesUndeliveredElementsAndOther_398" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DeferredRevenueArrangementLineItems_394" xlink:to="loc_ter_DeferredRevenueAndCustomerAdvancesUndeliveredElementsAndOther_398" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredRevenueArrangementByTypeTable" xlink:label="loc_us-gaap_DeferredRevenueArrangementByTypeTable_393" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DeferredRevenueArrangementLineItems_394" xlink:to="loc_us-gaap_DeferredRevenueArrangementByTypeTable_393" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_395" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DeferredRevenueArrangementByTypeTable_393" xlink:to="loc_dei_LegalEntityAxis_395" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_400" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_395" xlink:to="loc_dei_EntityDomain_400" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_400_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_395" xlink:to="loc_dei_EntityDomain_400_default" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ExtendedProductWarrantyAccrual" xlink:label="loc_us-gaap_ExtendedProductWarrantyAccrual_397" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DeferredRevenueArrangementLineItems_394" xlink:to="loc_us-gaap_ExtendedProductWarrantyAccrual_397" use="optional" order="8" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/WarrantyAccrualIncludedInOtherAccruedLiabilitiesDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProductWarrantyLiabilityLineItems" xlink:label="loc_us-gaap_ProductWarrantyLiabilityLineItems_404" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease" xlink:label="loc_us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease_410" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductWarrantyLiabilityLineItems_404" xlink:to="loc_us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease_410" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProductWarrantyLiabilityTable" xlink:label="loc_us-gaap_ProductWarrantyLiabilityTable_405" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ProductWarrantyLiabilityLineItems_404" xlink:to="loc_us-gaap_ProductWarrantyLiabilityTable_405" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_403" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ProductWarrantyLiabilityTable_405" xlink:to="loc_dei_LegalEntityAxis_403" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_406" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_403" xlink:to="loc_dei_EntityDomain_406" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_406_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_403" xlink:to="loc_dei_EntityDomain_406_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProductWarrantyAccrualWarrantiesIssued" xlink:label="loc_us-gaap_ProductWarrantyAccrualWarrantiesIssued_409" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductWarrantyLiabilityLineItems_404" xlink:to="loc_us-gaap_ProductWarrantyAccrualWarrantiesIssued_409" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProductWarrantyAccrual" xlink:label="loc_us-gaap_ProductWarrantyAccrual_407" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductWarrantyLiabilityLineItems_404" xlink:to="loc_us-gaap_ProductWarrantyAccrual_407" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProductWarrantyAccrualAdditionsFromBusinessAcquisition" xlink:label="loc_us-gaap_ProductWarrantyAccrualAdditionsFromBusinessAcquisition_408" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductWarrantyLiabilityLineItems_404" xlink:to="loc_us-gaap_ProductWarrantyAccrualAdditionsFromBusinessAcquisition_408" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProductWarrantyAccrualPayments" xlink:label="loc_us-gaap_ProductWarrantyAccrualPayments_411" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductWarrantyLiabilityLineItems_404" xlink:to="loc_us-gaap_ProductWarrantyAccrualPayments_411" use="optional" order="9" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ExtendedProductWarrantyOfShortAndLongTermDeferredRevenueAndCustomerAdvancesDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProductWarrantyLiabilityLineItems" xlink:label="loc_us-gaap_ProductWarrantyLiabilityLineItems_416" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ExtendedProductWarrantyAccrual" xlink:label="loc_us-gaap_ExtendedProductWarrantyAccrual_419" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductWarrantyLiabilityLineItems_416" xlink:to="loc_us-gaap_ExtendedProductWarrantyAccrual_419" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProductWarrantyLiabilityTable" xlink:label="loc_us-gaap_ProductWarrantyLiabilityTable_417" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ProductWarrantyLiabilityLineItems_416" xlink:to="loc_us-gaap_ProductWarrantyLiabilityTable_417" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_415" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ProductWarrantyLiabilityTable_417" xlink:to="loc_dei_LegalEntityAxis_415" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_418" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_415" xlink:to="loc_dei_EntityDomain_418" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_418_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_415" xlink:to="loc_dei_EntityDomain_418_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ExtendedProductWarrantyAccrualWarrantiesIssued" xlink:label="loc_us-gaap_ExtendedProductWarrantyAccrualWarrantiesIssued_420" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductWarrantyLiabilityLineItems_416" xlink:to="loc_us-gaap_ExtendedProductWarrantyAccrualWarrantiesIssued_420" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ExtendedProductWarrantyAccrualPayments" xlink:label="loc_us-gaap_ExtendedProductWarrantyAccrualPayments_421" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductWarrantyLiabilityLineItems_416" xlink:to="loc_us-gaap_ExtendedProductWarrantyAccrualPayments_421" use="optional" order="7" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfPrepaymentsAndOtherCurrentAssetsDetail">
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_PrepaidAndOtherCurrentAssetsLineItems" xlink:label="loc_ter_PrepaidAndOtherCurrentAssetsLineItems_396739" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PrepaidExpenseCurrent" xlink:label="loc_us-gaap_PrepaidExpenseCurrent_396744" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_PrepaidAndOtherCurrentAssetsLineItems_396739" xlink:to="loc_us-gaap_PrepaidExpenseCurrent_396744" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PrepaidTaxes" xlink:label="loc_us-gaap_PrepaidTaxes_396742" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_PrepaidAndOtherCurrentAssetsLineItems_396739" xlink:to="loc_us-gaap_PrepaidTaxes_396742" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_PrepaidMaintenanceAndOtherServices" xlink:label="loc_ter_PrepaidMaintenanceAndOtherServices_396741" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_PrepaidAndOtherCurrentAssetsLineItems_396739" xlink:to="loc_ter_PrepaidMaintenanceAndOtherServices_396741" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherPrepaidExpenseCurrent" xlink:label="loc_us-gaap_OtherPrepaidExpenseCurrent_396743" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_PrepaidAndOtherCurrentAssetsLineItems_396739" xlink:to="loc_us-gaap_OtherPrepaidExpenseCurrent_396743" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_PrepaidAndOtherCurrentAssetsTable" xlink:label="loc_ter_PrepaidAndOtherCurrentAssetsTable_396736" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ter_PrepaidAndOtherCurrentAssetsLineItems_396739" xlink:to="loc_ter_PrepaidAndOtherCurrentAssetsTable_396736" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_396737" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_PrepaidAndOtherCurrentAssetsTable_396736" xlink:to="loc_dei_LegalEntityAxis_396737" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_396738" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_396737" xlink:to="loc_dei_EntityDomain_396738" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_396738_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_396737" xlink:to="loc_dei_EntityDomain_396738_default" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ContractManufacturerAndSupplierPrepayments" xlink:label="loc_ter_ContractManufacturerAndSupplierPrepayments_396740" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_PrepaidAndOtherCurrentAssetsLineItems_396739" xlink:to="loc_ter_ContractManufacturerAndSupplierPrepayments_396740" use="optional" order="9" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/UsefulLivesOfAssetsDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_438" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives_445" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_438" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives_445" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_444" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_438" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_444" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_442" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_438" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_442" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_437" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_442" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_437" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_439" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_437" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_439" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_439_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_437" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_439_default" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LeaseholdImprovementsMember" xlink:label="loc_us-gaap_LeaseholdImprovementsMember_448" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_439" xlink:to="loc_us-gaap_LeaseholdImprovementsMember_448" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BuildingImprovementsMember" xlink:label="loc_us-gaap_BuildingImprovementsMember_447" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_439" xlink:to="loc_us-gaap_BuildingImprovementsMember_447" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BuildingMember" xlink:label="loc_us-gaap_BuildingMember_446" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_439" xlink:to="loc_us-gaap_BuildingMember_446" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_TestSystemsManufacturedInternallyMember" xlink:label="loc_ter_TestSystemsManufacturedInternallyMember_450" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_439" xlink:to="loc_ter_TestSystemsManufacturedInternallyMember_450" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FurnitureAndFixturesMember" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_449" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_439" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_449" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_MachineryEquipmentAndSoftwareMember" xlink:label="loc_ter_MachineryEquipmentAndSoftwareMember_826738" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_439" xlink:to="loc_ter_MachineryEquipmentAndSoftwareMember_826738" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_440" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_442" xlink:to="loc_srt_RangeAxis_440" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_441" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_440" xlink:to="loc_srt_RangeMember_441" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_441_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_440" xlink:to="loc_srt_RangeMember_441_default" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_454" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_441" xlink:to="loc_srt_MaximumMember_454" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_453" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_441" xlink:to="loc_srt_MinimumMember_453" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_436" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_442" xlink:to="loc_dei_LegalEntityAxis_436" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_443" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_436" xlink:to="loc_dei_EntityDomain_443" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_443_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_436" xlink:to="loc_dei_EntityDomain_443_default" use="optional" order="20" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/AcquisitionsAndInvestmentInOtherCompanyAdditionalInformationDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_459" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_BusinessAcquisitionPurchasePriceAllocationGoodwillNotExpectedTaxDeductibleAmount" xlink:label="loc_ter_BusinessAcquisitionPurchasePriceAllocationGoodwillNotExpectedTaxDeductibleAmount_470" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_459" xlink:to="loc_ter_BusinessAcquisitionPurchasePriceAllocationGoodwillNotExpectedTaxDeductibleAmount_470" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_477" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_459" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_477" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss" xlink:label="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_473" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_459" xlink:to="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_473" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_474" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_459" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_474" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh_469" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_459" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh_469" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_468" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_459" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_468" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual" xlink:label="loc_us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_471" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_459" xlink:to="loc_us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_471" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_476" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_459" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_476" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_478" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_459" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_478" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual" xlink:label="loc_us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual_472" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_459" xlink:to="loc_us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual_472" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_475" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_459" xlink:to="loc_us-gaap_Goodwill_475" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_466" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_459" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_466" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_467" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_459" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_467" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_QuantityOfMaterialToBeTransported" xlink:label="loc_ter_QuantityOfMaterialToBeTransported_677445" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_459" xlink:to="loc_ter_QuantityOfMaterialToBeTransported_677445" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:label="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_677446" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_459" xlink:to="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_677446" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityMethodInvestments" xlink:label="loc_us-gaap_EquityMethodInvestments_469580" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_459" xlink:to="loc_us-gaap_EquityMethodInvestments_469580" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_463" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_459" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_463" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_458" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_463" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_458" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_457" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_458" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_457" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_457_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_458" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_457_default" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_MobileIndustrialRobotsApsMember" xlink:label="loc_ter_MobileIndustrialRobotsApsMember_464" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_457" xlink:to="loc_ter_MobileIndustrialRobotsApsMember_464" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_EnergidTechnologiesCorporationMember" xlink:label="loc_ter_EnergidTechnologiesCorporationMember_465" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_457" xlink:to="loc_ter_EnergidTechnologiesCorporationMember_465" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_AutoguideLlcMember" xlink:label="loc_ter_AutoguideLlcMember_677444" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_457" xlink:to="loc_ter_AutoguideLlcMember_677444" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_LemsysMember" xlink:label="loc_ter_LemsysMember_415228" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_457" xlink:to="loc_ter_LemsysMember_415228" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_469021" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_463" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_469021" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_469022" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_469021" xlink:to="loc_us-gaap_RelatedPartyDomain_469022" use="optional" order="26" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_469022_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_469021" xlink:to="loc_us-gaap_RelatedPartyDomain_469022_default" use="optional" order="27" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_RealWarInMember" xlink:label="loc_ter_RealWarInMember_469023" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_469022" xlink:to="loc_ter_RealWarInMember_469023" use="optional" order="28" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DegreeOrExtentOfControlAxis" xlink:label="loc_ter_DegreeOrExtentOfControlAxis_469024" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_463" xlink:to="loc_ter_DegreeOrExtentOfControlAxis_469024" use="optional" order="29" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DegreeOrExtentOfControlDomain" xlink:label="loc_ter_DegreeOrExtentOfControlDomain_469025" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_ter_DegreeOrExtentOfControlAxis_469024" xlink:to="loc_ter_DegreeOrExtentOfControlDomain_469025" use="optional" order="30" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DegreeOrExtentOfControlDomain" xlink:label="loc_ter_DegreeOrExtentOfControlDomain_469025_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_ter_DegreeOrExtentOfControlAxis_469024" xlink:to="loc_ter_DegreeOrExtentOfControlDomain_469025_default" use="optional" order="31" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_677440" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_463" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_677440" use="optional" order="32" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_677441" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_677440" xlink:to="loc_us-gaap_SegmentDomain_677441" use="optional" order="33" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_677441_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_677440" xlink:to="loc_us-gaap_SegmentDomain_677441_default" use="optional" order="34" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_IndustrialAutomationMember" xlink:label="loc_ter_IndustrialAutomationMember_677442" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_677441" xlink:to="loc_ter_IndustrialAutomationMember_677442" use="optional" order="35" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_460" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_463" xlink:to="loc_dei_LegalEntityAxis_460" use="optional" order="36" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_479" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_460" xlink:to="loc_dei_EntityDomain_479" use="optional" order="37" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_479_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_460" xlink:to="loc_dei_EntityDomain_479_default" use="optional" order="38" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NonrecurringAdjustmentAxis" xlink:label="loc_us-gaap_NonrecurringAdjustmentAxis_461" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_463" xlink:to="loc_us-gaap_NonrecurringAdjustmentAxis_461" use="optional" order="39" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NonrecurringAdjustmentDomain" xlink:label="loc_us-gaap_NonrecurringAdjustmentDomain_462" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_NonrecurringAdjustmentAxis_461" xlink:to="loc_us-gaap_NonrecurringAdjustmentDomain_462" use="optional" order="40" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NonrecurringAdjustmentDomain" xlink:label="loc_us-gaap_NonrecurringAdjustmentDomain_462_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_NonrecurringAdjustmentAxis_461" xlink:to="loc_us-gaap_NonrecurringAdjustmentDomain_462_default" use="optional" order="41" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AcquisitionRelatedCostsMember" xlink:label="loc_us-gaap_AcquisitionRelatedCostsMember_481" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonrecurringAdjustmentDomain_462" xlink:to="loc_us-gaap_AcquisitionRelatedCostsMember_481" use="optional" order="42" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueAdjustmentToInventoryMember" xlink:label="loc_us-gaap_FairValueAdjustmentToInventoryMember_480" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonrecurringAdjustmentDomain_462" xlink:to="loc_us-gaap_FairValueAdjustmentToInventoryMember_480" use="optional" order="43" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_321733" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_463" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_321733" use="optional" order="44" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_321734" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_321733" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_321734" use="optional" order="45" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_321734_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_321733" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_321734_default" use="optional" order="46" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueByMeasurementBasisAxis" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_469027" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_463" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_469027" use="optional" order="47" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_470346" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_469027" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_470346" use="optional" order="48" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_470346_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_469027" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_470346_default" use="optional" order="49" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_470347" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_470346" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_470347" use="optional" order="50" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueByAssetClassAxis" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_469018" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_463" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_469018" use="optional" order="51" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_469019" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_469018" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_469019" use="optional" order="52" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_469019_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_469018" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_469019_default" use="optional" order="53" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment" xlink:label="loc_us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment_813388" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_459" xlink:to="loc_us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment_813388" use="optional" order="54" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_RepaymentOfDebtDemanded" xlink:label="loc_ter_RepaymentOfDebtDemanded_813390" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_459" xlink:to="loc_ter_RepaymentOfDebtDemanded_813390" use="optional" order="55" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/FinalAllocationOfPurchasePriceDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_486" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_496" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_486" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_496" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_490" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_486" xlink:to="loc_us-gaap_Goodwill_490" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentAssets_493" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_486" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentAssets_493" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_683213" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_486" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_683213" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_719022" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_486" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_719022" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_BusinessCombinationAllocationOfPurchasePriceTable" xlink:label="loc_ter_BusinessCombinationAllocationOfPurchasePriceTable_487" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_486" xlink:to="loc_ter_BusinessCombinationAllocationOfPurchasePriceTable_487" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_485" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_BusinessCombinationAllocationOfPurchasePriceTable_487" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_485" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_484" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_485" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_484" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_484_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_485" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_484_default" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_AutoguideLlcMember" xlink:label="loc_ter_AutoguideLlcMember_813433" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_484" xlink:to="loc_ter_AutoguideLlcMember_813433" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_MobileIndustrialRobotsApsMember" xlink:label="loc_ter_MobileIndustrialRobotsApsMember_489" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_484" xlink:to="loc_ter_MobileIndustrialRobotsApsMember_489" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_488" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_BusinessCombinationAllocationOfPurchasePriceTable_487" xlink:to="loc_dei_LegalEntityAxis_488" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_498" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_488" xlink:to="loc_dei_EntityDomain_498" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_498_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_488" xlink:to="loc_dei_EntityDomain_498_default" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_492" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_486" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_492" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_491" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_486" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_491" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_497" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_486" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_497" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilities" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilities_813662" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_486" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilities_813662" use="optional" order="18" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ComponentsOfIntangibleAssetsAndTheirEstimatedUsefulLivesAtAcquisitionDateDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_503" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_510" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_503" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_510" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FinitelivedIntangibleAssetsAcquired1" xlink:label="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_509" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_503" xlink:to="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_509" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTable" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTable_504" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_503" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTable_504" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_502" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTable_504" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_502" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_501" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_502" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_501" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_501_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_502" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_501_default" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_AutoguideLlcMember" xlink:label="loc_ter_AutoguideLlcMember_813441" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_501" xlink:to="loc_ter_AutoguideLlcMember_813441" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_505" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTable_504" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_505" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_506" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_505" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_506" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_506_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_505" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_506_default" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="loc_us-gaap_CustomerRelationshipsMember_513" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_506" xlink:to="loc_us-gaap_CustomerRelationshipsMember_513" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DevelopedTechnologyRightsMember" xlink:label="loc_us-gaap_DevelopedTechnologyRightsMember_511" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_506" xlink:to="loc_us-gaap_DevelopedTechnologyRightsMember_511" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OrderOrProductionBacklogMember" xlink:label="loc_us-gaap_OrderOrProductionBacklogMember_514" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_506" xlink:to="loc_us-gaap_OrderOrProductionBacklogMember_514" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TrademarksAndTradeNamesMember" xlink:label="loc_us-gaap_TrademarksAndTradeNamesMember_512" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_506" xlink:to="loc_us-gaap_TrademarksAndTradeNamesMember_512" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_507" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTable_504" xlink:to="loc_dei_LegalEntityAxis_507" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_515" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_507" xlink:to="loc_dei_EntityDomain_515" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_515_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_507" xlink:to="loc_dei_EntityDomain_515_default" use="optional" order="17" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ProFormaResultsUnderAcquisitionDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_520" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_BusinessAcquisitionProFormaInformationTable" xlink:label="loc_ter_BusinessAcquisitionProFormaInformationTable_521" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_520" xlink:to="loc_ter_BusinessAcquisitionProFormaInformationTable_521" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_522" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_BusinessAcquisitionProFormaInformationTable_521" xlink:to="loc_dei_LegalEntityAxis_522" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_528" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_522" xlink:to="loc_dei_EntityDomain_528" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_528_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_522" xlink:to="loc_dei_EntityDomain_528_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_519" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_BusinessAcquisitionProFormaInformationTable_521" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_519" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_518" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_519" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_518" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_518_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_519" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_518_default" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_MobileIndustrialRobotsApsMember" xlink:label="loc_ter_MobileIndustrialRobotsApsMember_523" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_518" xlink:to="loc_ter_MobileIndustrialRobotsApsMember_523" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss" xlink:label="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_525" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_520" xlink:to="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_525" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionsProFormaRevenue" xlink:label="loc_us-gaap_BusinessAcquisitionsProFormaRevenue_524" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_520" xlink:to="loc_us-gaap_BusinessAcquisitionsProFormaRevenue_524" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionProFormaEarningsPerShareBasic" xlink:label="loc_us-gaap_BusinessAcquisitionProFormaEarningsPerShareBasic_526" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_520" xlink:to="loc_us-gaap_BusinessAcquisitionProFormaEarningsPerShareBasic_526" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted" xlink:label="loc_us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted_527" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_520" xlink:to="loc_us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted_527" use="optional" order="12" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/RevenueAdditionalInformationDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_415308" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_415325" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_415308" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_415325" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_415305" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_415308" xlink:to="loc_us-gaap_StatementTable_415305" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_415312" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_415305" xlink:to="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_415312" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_415313" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_415312" xlink:to="loc_us-gaap_TypeOfAdoptionMember_415313" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_415313_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_415312" xlink:to="loc_us-gaap_TypeOfAdoptionMember_415313_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ContractWithCustomerDurationAxis" xlink:label="loc_us-gaap_ContractWithCustomerDurationAxis_415322" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_415305" xlink:to="loc_us-gaap_ContractWithCustomerDurationAxis_415322" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ContractWithCustomerDurationDomain" xlink:label="loc_us-gaap_ContractWithCustomerDurationDomain_415323" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ContractWithCustomerDurationAxis_415322" xlink:to="loc_us-gaap_ContractWithCustomerDurationDomain_415323" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ContractWithCustomerDurationDomain" xlink:label="loc_us-gaap_ContractWithCustomerDurationDomain_415323_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ContractWithCustomerDurationAxis_415322" xlink:to="loc_us-gaap_ContractWithCustomerDurationDomain_415323_default" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShortTermContractWithCustomerMember" xlink:label="loc_us-gaap_ShortTermContractWithCustomerMember_415324" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerDurationDomain_415323" xlink:to="loc_us-gaap_ShortTermContractWithCustomerMember_415324" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongTermContractWithCustomerMember" xlink:label="loc_us-gaap_LongTermContractWithCustomerMember_415327" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerDurationDomain_415323" xlink:to="loc_us-gaap_LongTermContractWithCustomerMember_415327" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_415306" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_415305" xlink:to="loc_us-gaap_StatementClassOfStockAxis_415306" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_415307" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_415306" xlink:to="loc_us-gaap_ClassOfStockDomain_415307" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_415307_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_415306" xlink:to="loc_us-gaap_ClassOfStockDomain_415307_default" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_415331" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_415305" xlink:to="loc_srt_RangeAxis_415331" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_415332" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_415331" xlink:to="loc_srt_RangeMember_415332" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_415332_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_415331" xlink:to="loc_srt_RangeMember_415332_default" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_415334" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_415332" xlink:to="loc_srt_MinimumMember_415334" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_415333" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_415332" xlink:to="loc_srt_MaximumMember_415333" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod2" xlink:label="loc_ter_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod2_415326" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_415308" xlink:to="loc_ter_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod2_415326" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_415339" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_415308" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_415339" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligation" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_830925" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_415308" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_830925" use="optional" order="21" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/DisaggregatedRevenueByPrimaryGeographicalMarketMajorProductLineAndTimingOfRevenueRecognitionDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DisaggregationOfRevenueLineItems" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_304" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Revenues" xlink:label="loc_us-gaap_Revenues_315" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_304" xlink:to="loc_us-gaap_Revenues_315" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DisaggregationOfRevenueTable" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_305" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_304" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_305" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_311" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_305" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_311" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_309" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_311" xlink:to="loc_us-gaap_SegmentDomain_309" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_309_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_311" xlink:to="loc_us-gaap_SegmentDomain_309_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_WirelessTestMember" xlink:label="loc_ter_WirelessTestMember_328" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_309" xlink:to="loc_ter_WirelessTestMember_328" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SemiconductorTestMember" xlink:label="loc_ter_SemiconductorTestMember_325" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_309" xlink:to="loc_ter_SemiconductorTestMember_325" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SystemsTestGroupMember" xlink:label="loc_ter_SystemsTestGroupMember_326" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_309" xlink:to="loc_ter_SystemsTestGroupMember_326" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_IndustrialAutomationMember" xlink:label="loc_ter_IndustrialAutomationMember_327" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_309" xlink:to="loc_ter_IndustrialAutomationMember_327" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CorporateAndOtherMember" xlink:label="loc_us-gaap_CorporateAndOtherMember_329" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_309" xlink:to="loc_us-gaap_CorporateAndOtherMember_329" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_StatementGeographicalAxis" xlink:label="loc_srt_StatementGeographicalAxis_312" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_305" xlink:to="loc_srt_StatementGeographicalAxis_312" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_310" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_312" xlink:to="loc_srt_SegmentGeographicalDomain_310" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_310_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_312" xlink:to="loc_srt_SegmentGeographicalDomain_310_default" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EMEAMember" xlink:label="loc_us-gaap_EMEAMember_331" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_310" xlink:to="loc_us-gaap_EMEAMember_331" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_AmericasMember" xlink:label="loc_srt_AmericasMember_330" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_310" xlink:to="loc_srt_AmericasMember_330" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_AsiaPacificMember" xlink:label="loc_srt_AsiaPacificMember_332" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_310" xlink:to="loc_srt_AsiaPacificMember_332" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TimingOfTransferOfGoodOrServiceAxis" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_313" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_305" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_313" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TimingOfTransferOfGoodOrServiceDomain" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_314" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_313" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_314" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TimingOfTransferOfGoodOrServiceDomain" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_314_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_313" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_314_default" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TransferredOverTimeMember" xlink:label="loc_us-gaap_TransferredOverTimeMember_334" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_314" xlink:to="loc_us-gaap_TransferredOverTimeMember_334" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TransferredAtPointInTimeMember" xlink:label="loc_us-gaap_TransferredAtPointInTimeMember_333" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_314" xlink:to="loc_us-gaap_TransferredAtPointInTimeMember_333" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_306" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_305" xlink:to="loc_dei_LegalEntityAxis_306" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_316" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_306" xlink:to="loc_dei_EntityDomain_316" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_316_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_306" xlink:to="loc_dei_EntityDomain_316_default" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_307" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_305" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_307" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_308" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_307" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_308" use="optional" order="26" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_308_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_307" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_308_default" use="optional" order="27" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_UniversalRobotsMember" xlink:label="loc_ter_UniversalRobotsMember_322" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_308" xlink:to="loc_ter_UniversalRobotsMember_322" use="optional" order="28" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SocMember" xlink:label="loc_ter_SocMember_317" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_308" xlink:to="loc_ter_SocMember_317" use="optional" order="29" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_MemoryMember" xlink:label="loc_ter_MemoryMember_318" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_308" xlink:to="loc_ter_MemoryMember_318" use="optional" order="30" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_AutoguideLlcMember" xlink:label="loc_ter_AutoguideLlcMember_677489" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_308" xlink:to="loc_ter_AutoguideLlcMember_677489" use="optional" order="31" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_MobileIndustrialRobotsApsMember" xlink:label="loc_ter_MobileIndustrialRobotsApsMember_323" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_308" xlink:to="loc_ter_MobileIndustrialRobotsApsMember_323" use="optional" order="32" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/InventoriesAdditionalInformationDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryLineItems" xlink:label="loc_us-gaap_InventoryLineItems_542" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryValuationReserves" xlink:label="loc_us-gaap_InventoryValuationReserves_544" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryLineItems_542" xlink:to="loc_us-gaap_InventoryValuationReserves_544" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryCurrentTable" xlink:label="loc_us-gaap_InventoryCurrentTable_541" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_InventoryLineItems_542" xlink:to="loc_us-gaap_InventoryCurrentTable_541" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_543" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InventoryCurrentTable_541" xlink:to="loc_dei_LegalEntityAxis_543" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_545" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_543" xlink:to="loc_dei_EntityDomain_545" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_545_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_543" xlink:to="loc_dei_EntityDomain_545_default" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/PropertyPlantAndEquipmentNetDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_549" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BuildingsAndImprovementsGross" xlink:label="loc_us-gaap_BuildingsAndImprovementsGross_553" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_549" xlink:to="loc_us-gaap_BuildingsAndImprovementsGross_553" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_560" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_549" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_560" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConstructionInProgressGross" xlink:label="loc_us-gaap_ConstructionInProgressGross_557" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_549" xlink:to="loc_us-gaap_ConstructionInProgressGross_557" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FurnitureAndFixturesGross" xlink:label="loc_us-gaap_FurnitureAndFixturesGross_555" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_549" xlink:to="loc_us-gaap_FurnitureAndFixturesGross_555" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Land" xlink:label="loc_us-gaap_Land_552" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_549" xlink:to="loc_us-gaap_Land_552" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LeaseholdImprovementsGross" xlink:label="loc_us-gaap_LeaseholdImprovementsGross_556" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_549" xlink:to="loc_us-gaap_LeaseholdImprovementsGross_556" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_558" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_549" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_558" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_559" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_549" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_559" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_550" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_549" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_550" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_548" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_550" xlink:to="loc_dei_LegalEntityAxis_548" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_551" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_548" xlink:to="loc_dei_EntityDomain_551" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_551_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_548" xlink:to="loc_dei_EntityDomain_551_default" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MachineryAndEquipmentGross" xlink:label="loc_us-gaap_MachineryAndEquipmentGross_554" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_549" xlink:to="loc_us-gaap_MachineryAndEquipmentGross_554" use="optional" order="13" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/PropertyPlantAndEquipmentAdditionalInformationDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_565" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_571" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_565" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_571" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Depreciation" xlink:label="loc_us-gaap_Depreciation_569" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_565" xlink:to="loc_us-gaap_Depreciation_569" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MachineryAndEquipmentGross" xlink:label="loc_us-gaap_MachineryAndEquipmentGross_570" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_565" xlink:to="loc_us-gaap_MachineryAndEquipmentGross_570" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_567" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_565" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_567" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_563" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_567" xlink:to="loc_dei_LegalEntityAxis_563" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_568" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_563" xlink:to="loc_dei_EntityDomain_568" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_568_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_563" xlink:to="loc_dei_EntityDomain_568_default" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_564" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_567" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_564" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_566" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_564" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_566" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_566_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_564" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_566_default" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_TestSystemsLeasedByCustomersMember" xlink:label="loc_ter_TestSystemsLeasedByCustomersMember_572" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_566" xlink:to="loc_ter_TestSystemsLeasedByCustomersMember_572" use="optional" order="11" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/FinancialInstrumentsAdditionalInformationDetail">
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_FinancialInstrumentsAndFairValueLineItems" xlink:label="loc_ter_FinancialInstrumentsAndFairValueLineItems_583" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesGrossRealizedGains" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesGrossRealizedGains_595" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_FinancialInstrumentsAndFairValueLineItems_583" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesGrossRealizedGains_595" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses_596" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_FinancialInstrumentsAndFairValueLineItems_583" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses_596" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh_598" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_FinancialInstrumentsAndFairValueLineItems_583" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh_598" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue_604" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_FinancialInstrumentsAndFairValueLineItems_583" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue_604" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskPercentage1" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_606" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_FinancialInstrumentsAndFairValueLineItems_583" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_606" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_FinancialInstrumentsAndFairValueTable" xlink:label="loc_ter_FinancialInstrumentsAndFairValueTable_584" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ter_FinancialInstrumentsAndFairValueLineItems_583" xlink:to="loc_ter_FinancialInstrumentsAndFairValueTable_584" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_576" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_FinancialInstrumentsAndFairValueTable_584" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_576" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_575" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_576" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_575" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_575_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_576" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_575_default" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_AutoguideLlcMember" xlink:label="loc_ter_AutoguideLlcMember_677544" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_575" xlink:to="loc_ter_AutoguideLlcMember_677544" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_578" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_FinancialInstrumentsAndFairValueTable_584" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_578" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_577" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_578" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_577" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_577_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_578" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_577_default" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccountsReceivableMember" xlink:label="loc_us-gaap_AccountsReceivableMember_591" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_577" xlink:to="loc_us-gaap_AccountsReceivableMember_591" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_588" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_FinancialInstrumentsAndFairValueTable_584" xlink:to="loc_srt_RangeAxis_588" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_589" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_588" xlink:to="loc_srt_RangeMember_589" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_589_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_588" xlink:to="loc_srt_RangeMember_589_default" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_609" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_589" xlink:to="loc_srt_MinimumMember_609" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentTypeAxis" xlink:label="loc_us-gaap_InvestmentTypeAxis_585" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_FinancialInstrumentsAndFairValueTable_584" xlink:to="loc_us-gaap_InvestmentTypeAxis_585" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_586" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_585" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_586" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_586_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_585" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_586_default" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DebtMutualFundsMember" xlink:label="loc_ter_DebtMutualFundsMember_607" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_586" xlink:to="loc_ter_DebtMutualFundsMember_607" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_587" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_FinancialInstrumentsAndFairValueTable_584" xlink:to="loc_dei_LegalEntityAxis_587" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_608" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_587" xlink:to="loc_dei_EntityDomain_608" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_608_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_587" xlink:to="loc_dei_EntityDomain_608_default" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskByTypeAxis" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_579" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_FinancialInstrumentsAndFairValueTable_584" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_579" use="optional" order="26" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_580" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_579" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_580" use="optional" order="27" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_580_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_579" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_580_default" use="optional" order="28" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_CustomerOneMember" xlink:label="loc_ter_CustomerOneMember_592" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_580" xlink:to="loc_ter_CustomerOneMember_592" use="optional" order="29" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_CustomerTwoMember" xlink:label="loc_ter_CustomerTwoMember_593" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_580" xlink:to="loc_ter_CustomerTwoMember_593" use="optional" order="30" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_582" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_FinancialInstrumentsAndFairValueTable_584" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_582" use="optional" order="31" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_581" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_582" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_581" use="optional" order="32" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_581_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_582" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_581_default" use="optional" order="33" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignExchangeContractMember" xlink:label="loc_us-gaap_ForeignExchangeContractMember_594" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_581" xlink:to="loc_us-gaap_ForeignExchangeContractMember_594" use="optional" order="34" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignCurrencyTransactionGainLossUnrealized" xlink:label="loc_us-gaap_ForeignCurrencyTransactionGainLossUnrealized_605" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_FinancialInstrumentsAndFairValueLineItems_583" xlink:to="loc_us-gaap_ForeignCurrencyTransactionGainLossUnrealized_605" use="optional" order="35" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ForeignCurrencyTransactionGainUnrealized" xlink:label="loc_ter_ForeignCurrencyTransactionGainUnrealized_499228" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_FinancialInstrumentsAndFairValueLineItems_583" xlink:to="loc_ter_ForeignCurrencyTransactionGainUnrealized_499228" use="optional" order="36" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_603" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_FinancialInstrumentsAndFairValueLineItems_583" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_603" use="optional" order="37" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ForeignCurrencyTransactionlossUnrealized" xlink:label="loc_ter_ForeignCurrencyTransactionlossUnrealized_499229" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_FinancialInstrumentsAndFairValueLineItems_583" xlink:to="loc_ter_ForeignCurrencyTransactionlossUnrealized_499229" use="optional" order="38" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfFairValueOfFinancialAssetsAndLiabilitiesMeasuredOnRecurringBasisDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_612" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecurities" xlink:label="loc_us-gaap_AvailableForSaleSecurities_623" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_612" xlink:to="loc_us-gaap_AvailableForSaleSecurities_623" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesEquitySecurities" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesEquitySecurities_624" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_612" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesEquitySecurities_624" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_628" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_612" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_628" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_CashAndCashEquivalentsAndAvailableForSaleSecuritiesFairValueDisclosure" xlink:label="loc_ter_CashAndCashEquivalentsAndAvailableForSaleSecuritiesFairValueDisclosure_625" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_612" xlink:to="loc_ter_CashAndCashEquivalentsAndAvailableForSaleSecuritiesFairValueDisclosure_625" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_621" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_612" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_621" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AssetsFairValueDisclosure" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_627" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_612" xlink:to="loc_us-gaap_AssetsFairValueDisclosure_627" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeAssets" xlink:label="loc_us-gaap_DerivativeAssets_626" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_612" xlink:to="loc_us-gaap_DerivativeAssets_626" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LiabilitiesFairValueDisclosure" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosure_630" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_612" xlink:to="loc_us-gaap_LiabilitiesFairValueDisclosure_630" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeLiabilities" xlink:label="loc_us-gaap_DerivativeLiabilities_629" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_612" xlink:to="loc_us-gaap_DerivativeLiabilities_629" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_613" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_612" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_613" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentTypeAxis" xlink:label="loc_us-gaap_InvestmentTypeAxis_618" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_613" xlink:to="loc_us-gaap_InvestmentTypeAxis_618" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_619" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_618" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_619" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_619_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_618" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_619_default" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashEquivalentsMember" xlink:label="loc_us-gaap_CashEquivalentsMember_636" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_619" xlink:to="loc_us-gaap_CashEquivalentsMember_636" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CertificatesOfDepositMember" xlink:label="loc_us-gaap_CertificatesOfDepositMember_641" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_619" xlink:to="loc_us-gaap_CertificatesOfDepositMember_641" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CorporateDebtSecuritiesMember" xlink:label="loc_us-gaap_CorporateDebtSecuritiesMember_639" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_619" xlink:to="loc_us-gaap_CorporateDebtSecuritiesMember_639" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashMember" xlink:label="loc_us-gaap_CashMember_635" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_619" xlink:to="loc_us-gaap_CashMember_635" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommercialPaperMember" xlink:label="loc_us-gaap_CommercialPaperMember_638" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_619" xlink:to="loc_us-gaap_CommercialPaperMember_638" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_EquityMutualFundsMember" xlink:label="loc_ter_EquityMutualFundsMember_645" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_619" xlink:to="loc_ter_EquityMutualFundsMember_645" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DebtMutualFundsMember" xlink:label="loc_ter_DebtMutualFundsMember_643" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_619" xlink:to="loc_ter_DebtMutualFundsMember_643" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignCorporateDebtSecuritiesMember" xlink:label="loc_us-gaap_ForeignCorporateDebtSecuritiesMember_644" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_619" xlink:to="loc_us-gaap_ForeignCorporateDebtSecuritiesMember_644" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember" xlink:label="loc_us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember_640" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_619" xlink:to="loc_us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember_640" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_637" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_619" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_637" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_615" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_613" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_615" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_616" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_615" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_616" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_616_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_615" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_616_default" use="optional" order="26" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementsRecurringMember" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_631" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_616" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_631" use="optional" order="27" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_614" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_613" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_614" use="optional" order="28" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_617" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_614" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_617" use="optional" order="29" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_617_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_614" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_617_default" use="optional" order="30" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_634" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_617" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_634" use="optional" order="31" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_633" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_617" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_633" use="optional" order="32" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_632" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_617" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_632" use="optional" order="33" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_620" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_613" xlink:to="loc_dei_LegalEntityAxis_620" use="optional" order="34" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_646" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_620" xlink:to="loc_dei_EntityDomain_646" use="optional" order="35" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_646_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_620" xlink:to="loc_dei_EntityDomain_646_default" use="optional" order="36" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfReportedFinancialAssetsAndLiabilitiesDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_651" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AssetsFairValueDisclosure" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_661" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_651" xlink:to="loc_us-gaap_AssetsFairValueDisclosure_661" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LiabilitiesFairValueDisclosure" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosure_662" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_651" xlink:to="loc_us-gaap_LiabilitiesFairValueDisclosure_662" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_652" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_651" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_652" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_649" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_652" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_649" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_650" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_649" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_650" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_650_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_649" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_650_default" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherCurrentLiabilitiesMember" xlink:label="loc_us-gaap_OtherCurrentLiabilitiesMember_660" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_650" xlink:to="loc_us-gaap_OtherCurrentLiabilitiesMember_660" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_654" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_652" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_654" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_655" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_654" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_655" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_655_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_654" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_655_default" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementsRecurringMember" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_663" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_655" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_663" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentTypeAxis" xlink:label="loc_us-gaap_InvestmentTypeAxis_657" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_652" xlink:to="loc_us-gaap_InvestmentTypeAxis_657" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_658" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_657" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_658" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_658_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_657" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_658_default" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashAndCashEquivalentsMember" xlink:label="loc_us-gaap_CashAndCashEquivalentsMember_667" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_658" xlink:to="loc_us-gaap_CashAndCashEquivalentsMember_667" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ContingentConsiderationMember" xlink:label="loc_ter_ContingentConsiderationMember_671" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_658" xlink:to="loc_ter_ContingentConsiderationMember_671" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_PrepaidExpenseMember" xlink:label="loc_ter_PrepaidExpenseMember_670" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_658" xlink:to="loc_ter_PrepaidExpenseMember_670" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_LongTermContingentConsiderationMember" xlink:label="loc_ter_LongTermContingentConsiderationMember_672" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_658" xlink:to="loc_ter_LongTermContingentConsiderationMember_672" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_LongTermMarketableSecuritiesMember" xlink:label="loc_ter_LongTermMarketableSecuritiesMember_669" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_658" xlink:to="loc_ter_LongTermMarketableSecuritiesMember_669" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_MarketableSecuritiesMember" xlink:label="loc_ter_MarketableSecuritiesMember_668" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_658" xlink:to="loc_ter_MarketableSecuritiesMember_668" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_653" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_652" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_653" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_656" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_653" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_656" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_656_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_653" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_656_default" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_664" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_656" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_664" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_665" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_656" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_665" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_666" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_656" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_666" use="optional" order="26" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_659" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_652" xlink:to="loc_dei_LegalEntityAxis_659" use="optional" order="27" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_673" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_659" xlink:to="loc_dei_EntityDomain_673" use="optional" order="28" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_673_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_659" xlink:to="loc_dei_EntityDomain_673_default" use="optional" order="29" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfChangesInFairValueOfLevel3ContingentConsiderationDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_676" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchases" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchases_680" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_676" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchases_680" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_683" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_676" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_683" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_677" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_676" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_677" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_678" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_677" xlink:to="loc_dei_LegalEntityAxis_678" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_685" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_678" xlink:to="loc_dei_EntityDomain_685" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_685_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_678" xlink:to="loc_dei_EntityDomain_685_default" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityForeignCurrencyExchangeRateImpact" xlink:label="loc_ter_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityForeignCurrencyExchangeRateImpact_681" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_676" xlink:to="loc_ter_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityForeignCurrencyExchangeRateImpact_681" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_679" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_676" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_679" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements_682" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_676" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements_682" use="optional" order="9" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfChangesInFairValueOfLevel3ContingentConsiderationParentheticalDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_690" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_691" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_690" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_691" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ContingentConsiderationPaymentAxis" xlink:label="loc_ter_ContingentConsiderationPaymentAxis_415356" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_691" xlink:to="loc_ter_ContingentConsiderationPaymentAxis_415356" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ContingentConsiderationPaymentDomain" xlink:label="loc_ter_ContingentConsiderationPaymentDomain_415357" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_ter_ContingentConsiderationPaymentAxis_415356" xlink:to="loc_ter_ContingentConsiderationPaymentDomain_415357" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ContingentConsiderationPaymentDomain" xlink:label="loc_ter_ContingentConsiderationPaymentDomain_415357_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_ter_ContingentConsiderationPaymentAxis_415356" xlink:to="loc_ter_ContingentConsiderationPaymentDomain_415357_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_689" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_691" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_689" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_688" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_689" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_688" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_688_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_689" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_688_default" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_AvionicsInterfaceTechnologiesLlcMember" xlink:label="loc_ter_AvionicsInterfaceTechnologiesLlcMember_694" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_688" xlink:to="loc_ter_AvionicsInterfaceTechnologiesLlcMember_694" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_MIRMember" xlink:label="loc_ter_MIRMember_321828" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_688" xlink:to="loc_ter_MIRMember_321828" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_UniversalRobotsMember" xlink:label="loc_ter_UniversalRobotsMember_693" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_688" xlink:to="loc_ter_UniversalRobotsMember_693" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_AutoguideLlcMember" xlink:label="loc_ter_AutoguideLlcMember_677541" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_688" xlink:to="loc_ter_AutoguideLlcMember_677541" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_763964" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_691" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_763964" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LossContingencyNatureDomain" xlink:label="loc_us-gaap_LossContingencyNatureDomain_763965" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_763964" xlink:to="loc_us-gaap_LossContingencyNatureDomain_763965" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LossContingencyNatureDomain" xlink:label="loc_us-gaap_LossContingencyNatureDomain_763965_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_763964" xlink:to="loc_us-gaap_LossContingencyNatureDomain_763965_default" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DisputeInRespectOfContingentConsiderationMember" xlink:label="loc_ter_DisputeInRespectOfContingentConsiderationMember_763966" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_763965" xlink:to="loc_ter_DisputeInRespectOfContingentConsiderationMember_763966" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities" xlink:label="loc_us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities_695" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_690" xlink:to="loc_us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities_695" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_696" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_690" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_696" use="optional" order="17" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/QuantitativeInformationAssociatedWithFairValueMeasurementOfLevel3FinancialInstrumentDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_704" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ContingentConsiderationFairValueInputsDiscountRate" xlink:label="loc_ter_ContingentConsiderationFairValueInputsDiscountRate_717" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_704" xlink:to="loc_ter_ContingentConsiderationFairValueInputsDiscountRate_717" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_705" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_704" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_705" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ContingentConsiderationByTypeAxis" xlink:label="loc_us-gaap_ContingentConsiderationByTypeAxis_702" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_705" xlink:to="loc_us-gaap_ContingentConsiderationByTypeAxis_702" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ContingentConsiderationTypeDomain" xlink:label="loc_us-gaap_ContingentConsiderationTypeDomain_703" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ContingentConsiderationByTypeAxis_702" xlink:to="loc_us-gaap_ContingentConsiderationTypeDomain_703" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ContingentConsiderationTypeDomain" xlink:label="loc_us-gaap_ContingentConsiderationTypeDomain_703_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ContingentConsiderationByTypeAxis_702" xlink:to="loc_us-gaap_ContingentConsiderationTypeDomain_703_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_RevenueOneMember" xlink:label="loc_ter_RevenueOneMember_713" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContingentConsiderationTypeDomain_703" xlink:to="loc_ter_RevenueOneMember_713" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_701" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_705" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_701" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_700" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_701" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_700" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_700_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_701" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_700_default" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_MobileIndustrialRobotsApsMember" xlink:label="loc_ter_MobileIndustrialRobotsApsMember_712" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_700" xlink:to="loc_ter_MobileIndustrialRobotsApsMember_712" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationTechniqueAxis" xlink:label="loc_us-gaap_ValuationTechniqueAxis_709" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_705" xlink:to="loc_us-gaap_ValuationTechniqueAxis_709" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationTechniqueDomain" xlink:label="loc_us-gaap_ValuationTechniqueDomain_710" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationTechniqueAxis_709" xlink:to="loc_us-gaap_ValuationTechniqueDomain_710" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationTechniqueDomain" xlink:label="loc_us-gaap_ValuationTechniqueDomain_710_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationTechniqueAxis_709" xlink:to="loc_us-gaap_ValuationTechniqueDomain_710_default" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_MonteCarloSimulationValuationModelMember" xlink:label="loc_ter_MonteCarloSimulationValuationModelMember_720" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_710" xlink:to="loc_ter_MonteCarloSimulationValuationModelMember_720" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_706" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_705" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_706" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_707" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_706" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_707" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_707_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_706" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_707_default" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_718" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_707" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_718" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_708" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_705" xlink:to="loc_dei_LegalEntityAxis_708" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_719" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_708" xlink:to="loc_dei_EntityDomain_719" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_719_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_708" xlink:to="loc_dei_EntityDomain_719_default" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_715" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_704" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_715" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ContingentConsiderationFairValueAssumptionsExpectedVolatilityRate" xlink:label="loc_ter_ContingentConsiderationFairValueAssumptionsExpectedVolatilityRate_716" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_704" xlink:to="loc_ter_ContingentConsiderationFairValueAssumptionsExpectedVolatilityRate_716" use="optional" order="23" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfCarryingAmountsAndFairValuesOfFinancialInstrumentsDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_737" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecurities" xlink:label="loc_us-gaap_AvailableForSaleSecurities_743" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_737" xlink:to="loc_us-gaap_AvailableForSaleSecurities_743" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_745" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_737" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_745" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_742" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_737" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_742" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConvertibleDebtFairValueDisclosures" xlink:label="loc_us-gaap_ConvertibleDebtFairValueDisclosures_747" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_737" xlink:to="loc_us-gaap_ConvertibleDebtFairValueDisclosures_747" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeAssets" xlink:label="loc_us-gaap_DerivativeAssets_744" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_737" xlink:to="loc_us-gaap_DerivativeAssets_744" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueByBalanceSheetGroupingTable" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_738" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_737" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_738" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueByMeasurementBasisAxis" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_739" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_738" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_739" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_311509" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_739" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_311509" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_311509_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_739" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_311509_default" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CarryingReportedAmountFairValueDisclosureMember" xlink:label="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_311510" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_311509" xlink:to="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_311510" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_311511" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_311509" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_311511" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_741" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_738" xlink:to="loc_dei_LegalEntityAxis_741" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_751" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_741" xlink:to="loc_dei_EntityDomain_751" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_751_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_741" xlink:to="loc_dei_EntityDomain_751_default" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeLiabilities" xlink:label="loc_us-gaap_DerivativeLiabilities_746" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_737" xlink:to="loc_us-gaap_DerivativeLiabilities_746" use="optional" order="15" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfAvailableForSaleMarketableSecuritiesDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_757" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecurities" xlink:label="loc_us-gaap_AvailableForSaleSecurities_771" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_757" xlink:to="loc_us-gaap_AvailableForSaleSecurities_771" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_769" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_757" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_769" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_770" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_757" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_770" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesTable" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_758" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_757" xlink:to="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_758" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_756" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_758" xlink:to="loc_dei_LegalEntityAxis_756" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_767" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_756" xlink:to="loc_dei_EntityDomain_767" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_767_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_756" xlink:to="loc_dei_EntityDomain_767_default" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentTypeAxis" xlink:label="loc_us-gaap_InvestmentTypeAxis_754" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_758" xlink:to="loc_us-gaap_InvestmentTypeAxis_754" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_755" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_754" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_755" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_755_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_754" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_755_default" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CertificatesOfDepositMember" xlink:label="loc_us-gaap_CertificatesOfDepositMember_763" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_755" xlink:to="loc_us-gaap_CertificatesOfDepositMember_763" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DebtMutualFundsMember" xlink:label="loc_ter_DebtMutualFundsMember_764" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_755" xlink:to="loc_ter_DebtMutualFundsMember_764" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CorporateDebtSecuritiesMember" xlink:label="loc_us-gaap_CorporateDebtSecuritiesMember_761" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_755" xlink:to="loc_us-gaap_CorporateDebtSecuritiesMember_761" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember" xlink:label="loc_us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember_762" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_755" xlink:to="loc_us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember_762" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommercialPaperMember" xlink:label="loc_us-gaap_CommercialPaperMember_760" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_755" xlink:to="loc_us-gaap_CommercialPaperMember_760" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignCorporateDebtSecuritiesMember" xlink:label="loc_us-gaap_ForeignCorporateDebtSecuritiesMember_765" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_755" xlink:to="loc_us-gaap_ForeignCorporateDebtSecuritiesMember_765" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_759" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_755" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_759" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesAmortizedCost" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesAmortizedCost_768" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_757" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesAmortizedCost_768" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue_772" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_757" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue_772" use="optional" order="19" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfReportedAvailableForSaleMarketableSecuritiesDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_778" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesTable" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_779" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_778" xlink:to="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_779" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentTypeAxis" xlink:label="loc_us-gaap_InvestmentTypeAxis_775" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_779" xlink:to="loc_us-gaap_InvestmentTypeAxis_775" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_776" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_775" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_776" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_776_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_775" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_776_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_MarketableSecuritiesMember" xlink:label="loc_ter_MarketableSecuritiesMember_780" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_776" xlink:to="loc_ter_MarketableSecuritiesMember_780" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_LongTermMarketableSecuritiesMember" xlink:label="loc_ter_LongTermMarketableSecuritiesMember_781" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_776" xlink:to="loc_ter_LongTermMarketableSecuritiesMember_781" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_777" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_779" xlink:to="loc_dei_LegalEntityAxis_777" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_782" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_777" xlink:to="loc_dei_EntityDomain_782" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_782_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_777" xlink:to="loc_dei_EntityDomain_782_default" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue_787" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_778" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue_787" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecurities" xlink:label="loc_us-gaap_AvailableForSaleSecurities_786" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_778" xlink:to="loc_us-gaap_AvailableForSaleSecurities_786" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_784" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_778" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_784" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_785" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_778" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_785" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesAmortizedCost" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesAmortizedCost_783" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_778" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesAmortizedCost_783" use="optional" order="14" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ContractualMaturitiesOfInvestmentsInDebtSecuritiesHeldDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_791" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_798" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_791" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_798" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesTable" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_792" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_791" xlink:to="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_792" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_790" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_792" xlink:to="loc_dei_LegalEntityAxis_790" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_793" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_790" xlink:to="loc_dei_EntityDomain_793" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_793_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_790" xlink:to="loc_dei_EntityDomain_793_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_799" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_791" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_799" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_803" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_791" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_803" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue_802" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_791" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue_802" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost_796" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_791" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost_796" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue_801" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_791" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue_801" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_800" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_791" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_800" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost_797" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_791" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost_797" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost_795" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_791" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost_795" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost_794" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_791" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost_794" use="optional" order="14" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfNotionalAmountOfDerivativesDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IntercompanyForeignCurrencyBalanceLineItems" xlink:label="loc_us-gaap_IntercompanyForeignCurrencyBalanceLineItems_810" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeAssetNotionalAmount" xlink:label="loc_us-gaap_DerivativeAssetNotionalAmount_825" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IntercompanyForeignCurrencyBalanceLineItems_810" xlink:to="loc_us-gaap_DerivativeAssetNotionalAmount_825" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfIntercompanyForeignCurrencyBalanceTable" xlink:label="loc_us-gaap_ScheduleOfIntercompanyForeignCurrencyBalanceTable_814" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IntercompanyForeignCurrencyBalanceLineItems_810" xlink:to="loc_us-gaap_ScheduleOfIntercompanyForeignCurrencyBalanceTable_814" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_811" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfIntercompanyForeignCurrencyBalanceTable_814" xlink:to="loc_dei_LegalEntityAxis_811" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_826" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_811" xlink:to="loc_dei_EntityDomain_826" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_826_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_811" xlink:to="loc_dei_EntityDomain_826_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PositionAxis" xlink:label="loc_us-gaap_PositionAxis_812" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfIntercompanyForeignCurrencyBalanceTable_814" xlink:to="loc_us-gaap_PositionAxis_812" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PositionDomain" xlink:label="loc_us-gaap_PositionDomain_813" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PositionAxis_812" xlink:to="loc_us-gaap_PositionDomain_813" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PositionDomain" xlink:label="loc_us-gaap_PositionDomain_813_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PositionAxis_812" xlink:to="loc_us-gaap_PositionDomain_813_default" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShortMember" xlink:label="loc_us-gaap_ShortMember_828" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PositionDomain_813" xlink:to="loc_us-gaap_ShortMember_828" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongMember" xlink:label="loc_us-gaap_LongMember_827" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PositionDomain_813" xlink:to="loc_us-gaap_LongMember_827" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_809" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfIntercompanyForeignCurrencyBalanceTable_814" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_809" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_808" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_809" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_808" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_808_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_809" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_808_default" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CurrencyAxis" xlink:label="loc_srt_CurrencyAxis_807" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfIntercompanyForeignCurrencyBalanceTable_814" xlink:to="loc_srt_CurrencyAxis_807" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/currency/2020/currency-2020-01-31.xsd#currency_AllCurrenciesDomain" xlink:label="loc_currency_AllCurrenciesDomain_806" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CurrencyAxis_807" xlink:to="loc_currency_AllCurrenciesDomain_806" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/currency/2020/currency-2020-01-31.xsd#currency_AllCurrenciesDomain" xlink:label="loc_currency_AllCurrenciesDomain_806_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CurrencyAxis_807" xlink:to="loc_currency_AllCurrenciesDomain_806_default" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/currency/2020/currency-2020-01-31.xsd#currency_EUR" xlink:label="loc_currency_EUR_819" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_currency_AllCurrenciesDomain_806" xlink:to="loc_currency_EUR_819" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/currency/2020/currency-2020-01-31.xsd#currency_SGD" xlink:label="loc_currency_SGD_820" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_currency_AllCurrenciesDomain_806" xlink:to="loc_currency_SGD_820" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/currency/2020/currency-2020-01-31.xsd#currency_TWD" xlink:label="loc_currency_TWD_816" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_currency_AllCurrenciesDomain_806" xlink:to="loc_currency_TWD_816" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/currency/2020/currency-2020-01-31.xsd#currency_JPY" xlink:label="loc_currency_JPY_815" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_currency_AllCurrenciesDomain_806" xlink:to="loc_currency_JPY_815" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/currency/2020/currency-2020-01-31.xsd#currency_KRW" xlink:label="loc_currency_KRW_817" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_currency_AllCurrenciesDomain_806" xlink:to="loc_currency_KRW_817" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/currency/2020/currency-2020-01-31.xsd#currency_CNY" xlink:label="loc_currency_CNY_822" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_currency_AllCurrenciesDomain_806" xlink:to="loc_currency_CNY_822" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/currency/2020/currency-2020-01-31.xsd#currency_PHP" xlink:label="loc_currency_PHP_821" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_currency_AllCurrenciesDomain_806" xlink:to="loc_currency_PHP_821" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/currency/2020/currency-2020-01-31.xsd#currency_GBP" xlink:label="loc_currency_GBP_818" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_currency_AllCurrenciesDomain_806" xlink:to="loc_currency_GBP_818" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeLiabilityNotionalAmount" xlink:label="loc_us-gaap_DerivativeLiabilityNotionalAmount_824" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IntercompanyForeignCurrencyBalanceLineItems_810" xlink:to="loc_us-gaap_DerivativeLiabilityNotionalAmount_824" use="optional" order="25" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionAtFairValueDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativesFairValueLineItems" xlink:label="loc_us-gaap_DerivativesFairValueLineItems_835" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable" xlink:label="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_836" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_835" xlink:to="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_836" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_831" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_836" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_831" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_832" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_831" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_832" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_832_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_831" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_832_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_PrepaidExpenseMember" xlink:label="loc_ter_PrepaidExpenseMember_840" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_832" xlink:to="loc_ter_PrepaidExpenseMember_840" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherCurrentLiabilitiesMember" xlink:label="loc_us-gaap_OtherCurrentLiabilitiesMember_841" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_832" xlink:to="loc_us-gaap_OtherCurrentLiabilitiesMember_841" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_839" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_836" xlink:to="loc_dei_LegalEntityAxis_839" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_847" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_839" xlink:to="loc_dei_EntityDomain_847" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_847_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_839" xlink:to="loc_dei_EntityDomain_847_default" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_834" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_836" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_834" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_833" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_834" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_833" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_833_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_834" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_833_default" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignExchangeForwardMember" xlink:label="loc_us-gaap_ForeignExchangeForwardMember_842" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_833" xlink:to="loc_us-gaap_ForeignExchangeForwardMember_842" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingDesignationAxis" xlink:label="loc_us-gaap_HedgingDesignationAxis_837" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_836" xlink:to="loc_us-gaap_HedgingDesignationAxis_837" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_838" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_837" xlink:to="loc_us-gaap_HedgingDesignationDomain_838" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_838_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_837" xlink:to="loc_us-gaap_HedgingDesignationDomain_838_default" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NondesignatedMember" xlink:label="loc_us-gaap_NondesignatedMember_846" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_838" xlink:to="loc_us-gaap_NondesignatedMember_846" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeAssets" xlink:label="loc_us-gaap_DerivativeAssets_843" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_835" xlink:to="loc_us-gaap_DerivativeAssets_843" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet" xlink:label="loc_us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet_845" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_835" xlink:to="loc_us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet_845" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeLiabilities" xlink:label="loc_us-gaap_DerivativeLiabilities_844" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_835" xlink:to="loc_us-gaap_DerivativeLiabilities_844" use="optional" order="20" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfEffectOfDerivativeInstrumentsInStatementOfOperationsRecognizedDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossLineItems" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_851" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_850" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_851" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_850" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_852" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_850" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_852" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_853" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_852" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_853" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_853_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_852" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_853_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpenseMember" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpenseMember_856" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_853" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpenseMember_856" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_854" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_850" xlink:to="loc_dei_LegalEntityAxis_854" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_857" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_854" xlink:to="loc_dei_EntityDomain_857" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_857_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_854" xlink:to="loc_dei_EntityDomain_857_default" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments" xlink:label="loc_us-gaap_GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments_855" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_851" xlink:to="loc_us-gaap_GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments_855" use="optional" order="9" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfEffectOfDerivativeInstrumentsInStatementOfOperationsRecognizedParentheticalDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossLineItems" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_861" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_860" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_861" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_860" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_862" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_860" xlink:to="loc_dei_LegalEntityAxis_862" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_864" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_862" xlink:to="loc_dei_EntityDomain_864" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_864_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_862" xlink:to="loc_dei_EntityDomain_864_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignCurrencyTransactionGainLossUnrealized" xlink:label="loc_us-gaap_ForeignCurrencyTransactionGainLossUnrealized_863" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_861" xlink:to="loc_us-gaap_ForeignCurrencyTransactionGainLossUnrealized_863" use="optional" order="5" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/LeasesAdditionalInformationDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_396714" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_396711" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_396714" xlink:to="loc_us-gaap_StatementTable_396711" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableLeaseCost" xlink:label="loc_us-gaap_VariableLeaseCost_396716" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_396714" xlink:to="loc_us-gaap_VariableLeaseCost_396716" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShortTermLeaseCost" xlink:label="loc_us-gaap_ShortTermLeaseCost_396717" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_396714" xlink:to="loc_us-gaap_ShortTermLeaseCost_396717" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LeaseCost" xlink:label="loc_us-gaap_LeaseCost_396715" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_396714" xlink:to="loc_us-gaap_LeaseCost_396715" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:label="loc_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_415289" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_396714" xlink:to="loc_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_415289" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:label="loc_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_415290" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_396714" xlink:to="loc_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_415290" use="optional" order="6" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/SupplementalCashFlowInformationRelatedToLeasesDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_396668" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeasePayments" xlink:label="loc_us-gaap_OperatingLeasePayments_396669" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_396668" xlink:to="loc_us-gaap_OperatingLeasePayments_396669" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" xlink:label="loc_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_396670" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_396668" xlink:to="loc_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_396670" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_396665" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_396668" xlink:to="loc_us-gaap_StatementTable_396665" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="3" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfOperatingLeaseMaturityDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_396691" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_396693" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_396691" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_396693" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_396694" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_396691" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_396694" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_396688" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_396691" xlink:to="loc_us-gaap_StatementTable_396688" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_396689" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_396688" xlink:to="loc_us-gaap_StatementClassOfStockAxis_396689" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_396690" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_396689" xlink:to="loc_us-gaap_ClassOfStockDomain_396690" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_396690_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_396689" xlink:to="loc_us-gaap_ClassOfStockDomain_396690_default" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_396696" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_396691" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_396696" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_396697" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_396691" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_396697" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_396699" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_396691" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_396699" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseLiability" xlink:label="loc_us-gaap_OperatingLeaseLiability_396700" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_396691" xlink:to="loc_us-gaap_OperatingLeaseLiability_396700" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_396695" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_396691" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_396695" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_396698" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_396691" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_396698" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_814332" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_396691" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_814332" use="optional" order="13" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/DebtAdditionalInformationDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_872" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRightsIssued" xlink:label="loc_ter_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRightsIssued_899" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_ter_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRightsIssued_899" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentConvertibleCarryingAmountOfTheEquityComponent" xlink:label="loc_us-gaap_DebtInstrumentConvertibleCarryingAmountOfTheEquityComponent_900" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_DebtInstrumentConvertibleCarryingAmountOfTheEquityComponent_900" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_910" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_910" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_AntidilutionAdjustmentsOfConvertibleNoteHedges" xlink:label="loc_ter_AntidilutionAdjustmentsOfConvertibleNoteHedges_898" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_ter_AntidilutionAdjustmentsOfConvertibleNoteHedges_898" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentConvertibleConversionPrice1" xlink:label="loc_us-gaap_DebtInstrumentConvertibleConversionPrice1_897" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_DebtInstrumentConvertibleConversionPrice1_897" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtConversionConvertedInstrumentExpirationOrDueDateDayMonthAndYear" xlink:label="loc_us-gaap_DebtConversionConvertedInstrumentExpirationOrDueDateDayMonthAndYear_892" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_DebtConversionConvertedInstrumentExpirationOrDueDateDayMonthAndYear_892" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_901" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_901" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_884" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_884" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DebtInstrumentIssuanceCostsAmortizationPeriod" xlink:label="loc_ter_DebtInstrumentIssuanceCostsAmortizationPeriod_903" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_ter_DebtInstrumentIssuanceCostsAmortizationPeriod_903" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentConvertibleBeneficialConversionFeature" xlink:label="loc_us-gaap_DebtInstrumentConvertibleBeneficialConversionFeature_906" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_DebtInstrumentConvertibleBeneficialConversionFeature_906" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DebtInstrumentConvertibleMaximumThresholdPercentage" xlink:label="loc_ter_DebtInstrumentConvertibleMaximumThresholdPercentage_896" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_ter_DebtInstrumentConvertibleMaximumThresholdPercentage_896" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentConvertibleRemainingDiscountAmortizationPeriod1" xlink:label="loc_us-gaap_DebtInstrumentConvertibleRemainingDiscountAmortizationPeriod1_905" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_DebtInstrumentConvertibleRemainingDiscountAmortizationPeriod1_905" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays1" xlink:label="loc_us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays1_894" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays1_894" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger" xlink:label="loc_us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger_895" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger_895" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentMaturityDate" xlink:label="loc_us-gaap_DebtInstrumentMaturityDate_889" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_DebtInstrumentMaturityDate_889" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentConvertibleThresholdTradingDays" xlink:label="loc_us-gaap_DebtInstrumentConvertibleThresholdTradingDays_893" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_DebtInstrumentConvertibleThresholdTradingDays_893" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_883" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_883" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_874" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_DebtInstrumentTable_874" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:label="loc_us-gaap_CreditFacilityAxis_867" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_874" xlink:to="loc_us-gaap_CreditFacilityAxis_867" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_868" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_867" xlink:to="loc_us-gaap_CreditFacilityDomain_868" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_868_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_867" xlink:to="loc_us-gaap_CreditFacilityDomain_868_default" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_880" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_868" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_880" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_871" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_874" xlink:to="loc_us-gaap_DebtInstrumentAxis_871" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_873" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_871" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_873" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_873_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_871" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_873_default" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_OnePointTwoFivePercentConvertibleSeniorUnsecuredNotesDueDecemberFifteenTwoThousandTwentyThreeMember" xlink:label="loc_ter_OnePointTwoFivePercentConvertibleSeniorUnsecuredNotesDueDecemberFifteenTwoThousandTwentyThreeMember_913" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_873" xlink:to="loc_ter_OnePointTwoFivePercentConvertibleSeniorUnsecuredNotesDueDecemberFifteenTwoThousandTwentyThreeMember_913" use="optional" order="26" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtConversionByUniqueDescriptionAxis" xlink:label="loc_us-gaap_DebtConversionByUniqueDescriptionAxis_869" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_874" xlink:to="loc_us-gaap_DebtConversionByUniqueDescriptionAxis_869" use="optional" order="27" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtConversionNameDomain" xlink:label="loc_us-gaap_DebtConversionNameDomain_870" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtConversionByUniqueDescriptionAxis_869" xlink:to="loc_us-gaap_DebtConversionNameDomain_870" use="optional" order="28" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtConversionNameDomain" xlink:label="loc_us-gaap_DebtConversionNameDomain_870_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtConversionByUniqueDescriptionAxis_869" xlink:to="loc_us-gaap_DebtConversionNameDomain_870_default" use="optional" order="29" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_OptionOneMember" xlink:label="loc_ter_OptionOneMember_881" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtConversionNameDomain_870" xlink:to="loc_ter_OptionOneMember_881" use="optional" order="30" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_OptionTwoMember" xlink:label="loc_ter_OptionTwoMember_882" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtConversionNameDomain_870" xlink:to="loc_ter_OptionTwoMember_882" use="optional" order="31" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_875" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_874" xlink:to="loc_dei_LegalEntityAxis_875" use="optional" order="32" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_914" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_875" xlink:to="loc_dei_EntityDomain_914" use="optional" order="33" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_914_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_875" xlink:to="loc_dei_EntityDomain_914_default" use="optional" order="34" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_876" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_874" xlink:to="loc_srt_RangeAxis_876" use="optional" order="35" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_877" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_876" xlink:to="loc_srt_RangeMember_877" use="optional" order="36" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_877_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_876" xlink:to="loc_srt_RangeMember_877_default" use="optional" order="37" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_915" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_877" xlink:to="loc_srt_MaximumMember_915" use="optional" order="38" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_916" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_877" xlink:to="loc_srt_MinimumMember_916" use="optional" order="39" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableRateAxis" xlink:label="loc_us-gaap_VariableRateAxis_878" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_874" xlink:to="loc_us-gaap_VariableRateAxis_878" use="optional" order="40" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_879" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_878" xlink:to="loc_us-gaap_VariableRateDomain_879" use="optional" order="41" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_879_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_878" xlink:to="loc_us-gaap_VariableRateDomain_879_default" use="optional" order="42" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BaseRateMember" xlink:label="loc_us-gaap_BaseRateMember_917" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_879" xlink:to="loc_us-gaap_BaseRateMember_917" use="optional" order="43" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LondonInterbankOfferedRateLIBORMember" xlink:label="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_918" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_879" xlink:to="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_918" use="optional" order="44" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CollateralAxis" xlink:label="loc_us-gaap_CollateralAxis_718953" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_874" xlink:to="loc_us-gaap_CollateralAxis_718953" use="optional" order="45" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CollateralDomain" xlink:label="loc_us-gaap_CollateralDomain_718954" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CollateralAxis_718953" xlink:to="loc_us-gaap_CollateralDomain_718954" use="optional" order="46" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CollateralDomain" xlink:label="loc_us-gaap_CollateralDomain_718954_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CollateralAxis_718953" xlink:to="loc_us-gaap_CollateralDomain_718954_default" use="optional" order="47" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CollateralPledgedMember" xlink:label="loc_us-gaap_CollateralPledgedMember_718955" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_718954" xlink:to="loc_us-gaap_CollateralPledgedMember_718955" use="optional" order="48" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_826521" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_874" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_826521" use="optional" order="49" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_826522" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_826521" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_826522" use="optional" order="50" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_826522_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_826521" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_826522_default" use="optional" order="51" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="loc_us-gaap_SubsequentEventMember_826523" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_826522" xlink:to="loc_us-gaap_SubsequentEventMember_826523" use="optional" order="52" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityAxis" xlink:label="loc_us-gaap_LineOfCreditFacilityAxis_828925" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_874" xlink:to="loc_us-gaap_LineOfCreditFacilityAxis_828925" use="optional" order="53" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityLenderDomain" xlink:label="loc_us-gaap_LineOfCreditFacilityLenderDomain_828926" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LineOfCreditFacilityAxis_828925" xlink:to="loc_us-gaap_LineOfCreditFacilityLenderDomain_828926" use="optional" order="54" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityLenderDomain" xlink:label="loc_us-gaap_LineOfCreditFacilityLenderDomain_828926_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LineOfCreditFacilityAxis_828925" xlink:to="loc_us-gaap_LineOfCreditFacilityLenderDomain_828926_default" use="optional" order="55" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_TruistBankMember" xlink:label="loc_ter_TruistBankMember_828928" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLenderDomain_828926" xlink:to="loc_ter_TruistBankMember_828928" use="optional" order="56" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_828909" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_874" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_828909" use="optional" order="57" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_828910" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_828909" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_828910" use="optional" order="58" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_828910_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_828909" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_828910_default" use="optional" order="59" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ConvertibleCommonSharesMember" xlink:label="loc_ter_ConvertibleCommonSharesMember_828912" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_828910" xlink:to="loc_ter_ConvertibleCommonSharesMember_828912" use="optional" order="60" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_StatementScenarioAxis" xlink:label="loc_srt_StatementScenarioAxis_828914" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_874" xlink:to="loc_srt_StatementScenarioAxis_828914" use="optional" order="61" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ScenarioUnspecifiedDomain" xlink:label="loc_srt_ScenarioUnspecifiedDomain_828915" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementScenarioAxis_828914" xlink:to="loc_srt_ScenarioUnspecifiedDomain_828915" use="optional" order="62" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ScenarioUnspecifiedDomain" xlink:label="loc_srt_ScenarioUnspecifiedDomain_828915_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementScenarioAxis_828914" xlink:to="loc_srt_ScenarioUnspecifiedDomain_828915_default" use="optional" order="63" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentUnamortizedDiscount" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscount_904" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscount_904" use="optional" order="64" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredFinanceCostsNet" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_902" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_902" use="optional" order="65" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_PaymentsForConvertibleNoteHedgeNetFinancingActivities" xlink:label="loc_ter_PaymentsForConvertibleNoteHedgeNetFinancingActivities_886" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_ter_PaymentsForConvertibleNoteHedgeNetFinancingActivities_886" use="optional" order="66" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_887" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_887" use="optional" order="67" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_908" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_908" use="optional" order="68" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentTerm" xlink:label="loc_us-gaap_DebtInstrumentTerm_907" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_DebtInstrumentTerm_907" use="optional" order="69" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentFrequencyOfPeriodicPayment" xlink:label="loc_us-gaap_DebtInstrumentFrequencyOfPeriodicPayment_890" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_DebtInstrumentFrequencyOfPeriodicPayment_890" use="optional" order="70" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_718949" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_718949" use="optional" order="71" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityCapacityAvailableForSpecificPurposeOtherThanForTradePurchases" xlink:label="loc_us-gaap_LineOfCreditFacilityCapacityAvailableForSpecificPurposeOtherThanForTradePurchases_718950" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_LineOfCreditFacilityCapacityAvailableForSpecificPurposeOtherThanForTradePurchases_718950" use="optional" order="72" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityInterestRateDescription" xlink:label="loc_us-gaap_LineOfCreditFacilityInterestRateDescription_718952" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_LineOfCreditFacilityInterestRateDescription_718952" use="optional" order="73" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage" xlink:label="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_911" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_911" use="optional" order="74" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodShares" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_888" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_888" use="optional" order="75" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromDebtNetOfIssuanceCosts" xlink:label="loc_us-gaap_ProceedsFromDebtNetOfIssuanceCosts_885" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_ProceedsFromDebtNetOfIssuanceCosts_885" use="optional" order="76" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongTermDebtTerm" xlink:label="loc_us-gaap_LongTermDebtTerm_720568" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_LongTermDebtTerm_720568" use="optional" order="77" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_NumberOfHoldersExcerisedTheConversionOption" xlink:label="loc_ter_NumberOfHoldersExcerisedTheConversionOption_826524" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_ter_NumberOfHoldersExcerisedTheConversionOption_826524" use="optional" order="78" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtConversionConvertedInstrumentAmount1" xlink:label="loc_us-gaap_DebtConversionConvertedInstrumentAmount1_828892" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_DebtConversionConvertedInstrumentAmount1_828892" use="optional" order="79" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RedeemableNoncontrollingInterestEquityCommonCarryingAmount" xlink:label="loc_us-gaap_RedeemableNoncontrollingInterestEquityCommonCarryingAmount_828919" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_us-gaap_RedeemableNoncontrollingInterestEquityCommonCarryingAmount_828919" use="optional" order="80" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DebtInstrumentBaseRatePercentage" xlink:label="loc_ter_DebtInstrumentBaseRatePercentage_828924" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_872" xlink:to="loc_ter_DebtInstrumentBaseRatePercentage_828924" use="optional" order="81" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ComponentsOfConvertibleSeniorNotesDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_922" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_927" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_922" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_927" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_924" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_922" xlink:to="loc_us-gaap_DebtInstrumentTable_924" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_925" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_924" xlink:to="loc_dei_LegalEntityAxis_925" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_930" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_925" xlink:to="loc_dei_EntityDomain_930" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_930_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_925" xlink:to="loc_dei_EntityDomain_930_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_921" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_924" xlink:to="loc_us-gaap_DebtInstrumentAxis_921" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_923" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_921" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_923" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_923_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_921" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_923_default" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_OnePointTwoFivePercentConvertibleSeniorUnsecuredNotesDueDecemberFifteenTwoThousandTwentyThreeMember" xlink:label="loc_ter_OnePointTwoFivePercentConvertibleSeniorUnsecuredNotesDueDecemberFifteenTwoThousandTwentyThreeMember_929" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_923" xlink:to="loc_ter_OnePointTwoFivePercentConvertibleSeniorUnsecuredNotesDueDecemberFifteenTwoThousandTwentyThreeMember_929" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_926" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_922" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_926" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConvertibleDebt" xlink:label="loc_us-gaap_ConvertibleDebt_928" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_922" xlink:to="loc_us-gaap_ConvertibleDebt_928" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConvertibleDebtNoncurrent" xlink:label="loc_us-gaap_ConvertibleDebtNoncurrent_826515" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_922" xlink:to="loc_us-gaap_ConvertibleDebtNoncurrent_826515" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConvertibleDebtCurrent" xlink:label="loc_us-gaap_ConvertibleDebtCurrent_826512" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_922" xlink:to="loc_us-gaap_ConvertibleDebtCurrent_826512" use="optional" order="13" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/InterestExpenseOnConvertibleSeniorNotesDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_933" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ContractualInterestExpenseOnCoupon" xlink:label="loc_ter_ContractualInterestExpenseOnCoupon_936" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_933" xlink:to="loc_ter_ContractualInterestExpenseOnCoupon_936" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_934" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_933" xlink:to="loc_us-gaap_DebtInstrumentTable_934" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_935" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_934" xlink:to="loc_dei_LegalEntityAxis_935" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_939" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_935" xlink:to="loc_dei_EntityDomain_939" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_939_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_935" xlink:to="loc_dei_EntityDomain_939_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestExpenseDebt" xlink:label="loc_us-gaap_InterestExpenseDebt_938" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_933" xlink:to="loc_us-gaap_InterestExpenseDebt_938" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AmortizationOfDebtDiscountPremium" xlink:label="loc_us-gaap_AmortizationOfDebtDiscountPremium_937" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_933" xlink:to="loc_us-gaap_AmortizationOfDebtDiscountPremium_937" use="optional" order="7" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ChangesInAccumulatedOtherComprehensiveLossIncomeDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_942" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_943" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_942" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_943" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_947" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_943" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_947" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_945" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_947" xlink:to="loc_us-gaap_EquityComponentDomain_945" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_945_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_947" xlink:to="loc_us-gaap_EquityComponentDomain_945_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMember" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMember_958" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_945" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMember_958" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember" xlink:label="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_957" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_945" xlink:to="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_957" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ForeignCurrencyTranslationAdjustmentsMember" xlink:label="loc_ter_ForeignCurrencyTranslationAdjustmentsMember_956" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_945" xlink:to="loc_ter_ForeignCurrencyTranslationAdjustmentsMember_956" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_959" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_945" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_959" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_946" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_943" xlink:to="loc_dei_LegalEntityAxis_946" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_960" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_946" xlink:to="loc_dei_EntityDomain_960" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_960_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_946" xlink:to="loc_dei_EntityDomain_960_default" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_944" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_943" xlink:to="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_944" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_948" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_944" xlink:to="loc_us-gaap_TypeOfAdoptionMember_948" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_948_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_944" xlink:to="loc_us-gaap_TypeOfAdoptionMember_948_default" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_951" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_942" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_951" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_952" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_942" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_952" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_950" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_942" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_950" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_949" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_942" xlink:to="loc_us-gaap_StockholdersEquity_949" use="optional" order="18" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ChangesInAccumulatedOtherComprehensiveLossIncomeParentheticalDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_964" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentTax" xlink:label="loc_ter_AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentTax_977" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_964" xlink:to="loc_ter_AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentTax_977" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_965" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_964" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_965" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_969" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_965" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_969" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_967" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_969" xlink:to="loc_us-gaap_EquityComponentDomain_967" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_967_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_969" xlink:to="loc_us-gaap_EquityComponentDomain_967_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ForeignCurrencyTranslationAdjustmentsMember" xlink:label="loc_ter_ForeignCurrencyTranslationAdjustmentsMember_979" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_967" xlink:to="loc_ter_ForeignCurrencyTranslationAdjustmentsMember_979" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember" xlink:label="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_980" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_967" xlink:to="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_980" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMember" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMember_981" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_967" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMember_981" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_966" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_965" xlink:to="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_966" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_970" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_966" xlink:to="loc_us-gaap_TypeOfAdoptionMember_970" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_970_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_966" xlink:to="loc_us-gaap_TypeOfAdoptionMember_970_default" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_968" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_965" xlink:to="loc_dei_LegalEntityAxis_968" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_982" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_968" xlink:to="loc_dei_EntityDomain_982" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_982_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_968" xlink:to="loc_dei_EntityDomain_982_default" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationFromAociCurrentPeriodTax" xlink:label="loc_us-gaap_ReclassificationFromAociCurrentPeriodTax_972" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_964" xlink:to="loc_us-gaap_ReclassificationFromAociCurrentPeriodTax_972" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax" xlink:label="loc_ter_AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax_976" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_964" xlink:to="loc_ter_AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax_976" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax_971" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_964" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax_971" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansTax" xlink:label="loc_ter_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansTax_978" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_964" xlink:to="loc_ter_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansTax_978" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossTax_973" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_964" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossTax_973" use="optional" order="19" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ReclassificationsOutOfAccumulatedOtherComprehensiveIncomeToStatementsOfOperationsDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems" xlink:label="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems_988" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax_499266" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems_988" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax_499266" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_998" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems_988" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_998" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_991" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems_988" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_991" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_992" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_991" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_992" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_986" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_992" xlink:to="loc_us-gaap_EquityComponentDomain_986" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_986_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_992" xlink:to="loc_us-gaap_EquityComponentDomain_986_default" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMember" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMember_994" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_986" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMember_994" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_995" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_986" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_995" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_989" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_991" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_989" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_990" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_989" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_990" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_990_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_989" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_990_default" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_987" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_991" xlink:to="loc_dei_LegalEntityAxis_987" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_996" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_987" xlink:to="loc_dei_EntityDomain_996" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_996_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_987" xlink:to="loc_dei_EntityDomain_996_default" use="optional" order="14" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ReclassificationsOutOfAccumulatedOtherComprehensiveIncomeToStatementsOfOperationsParentheticalDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems" xlink:label="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems_1004" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationFromAociCurrentPeriodTax" xlink:label="loc_us-gaap_ReclassificationFromAociCurrentPeriodTax_1010" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems_1004" xlink:to="loc_us-gaap_ReclassificationFromAociCurrentPeriodTax_1010" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_1005" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems_1004" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_1005" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1003" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_1005" xlink:to="loc_dei_LegalEntityAxis_1003" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1009" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1003" xlink:to="loc_dei_EntityDomain_1009" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1009_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1003" xlink:to="loc_dei_EntityDomain_1009_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_1006" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_1005" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_1006" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_1002" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_1006" xlink:to="loc_us-gaap_EquityComponentDomain_1002" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_1002_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_1006" xlink:to="loc_us-gaap_EquityComponentDomain_1002_default" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember" xlink:label="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_1007" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_1002" xlink:to="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_1007" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMember" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMember_1008" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_1002" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMember_1008" use="optional" order="10" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/GoodwillAndIntangibleAssetsAdditionalInformationDetail">
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_GoodwillAndIntangibleAssetsDisclosureLineItems" xlink:label="loc_ter_GoodwillAndIntangibleAssetsDisclosureLineItems_1017" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_GoodwillAndIntangibleAssetsDisclosureTable" xlink:label="loc_ter_GoodwillAndIntangibleAssetsDisclosureTable_1018" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ter_GoodwillAndIntangibleAssetsDisclosureLineItems_1017" xlink:to="loc_ter_GoodwillAndIntangibleAssetsDisclosureTable_1018" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_1014" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_GoodwillAndIntangibleAssetsDisclosureTable_1018" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_1014" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_1013" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_1014" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_1013" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_1013_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_1014" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_1013_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskByTypeAxis" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_1015" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_GoodwillAndIntangibleAssetsDisclosureTable_1018" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_1015" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_1016" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_1015" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_1016" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_1016_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_1015" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_1016_default" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1019" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_GoodwillAndIntangibleAssetsDisclosureTable_1018" xlink:to="loc_dei_LegalEntityAxis_1019" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1033" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1019" xlink:to="loc_dei_EntityDomain_1033" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1033_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1019" xlink:to="loc_dei_EntityDomain_1033_default" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_1020" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_GoodwillAndIntangibleAssetsDisclosureTable_1018" xlink:to="loc_srt_RangeAxis_1020" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_1021" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_1020" xlink:to="loc_srt_RangeMember_1021" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_1021_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_1020" xlink:to="loc_srt_RangeMember_1021_default" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_1023" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_GoodwillAndIntangibleAssetsDisclosureTable_1018" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_1023" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_1022" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_1023" xlink:to="loc_us-gaap_SegmentDomain_1022" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_1022_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_1023" xlink:to="loc_us-gaap_SegmentDomain_1022_default" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount" xlink:label="loc_us-gaap_ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount_813618" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_GoodwillAndIntangibleAssetsDisclosureLineItems_1017" xlink:to="loc_us-gaap_ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount_813618" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReportingUnitAmountOfFairValueInExcessOfCarryingAmount" xlink:label="loc_us-gaap_ReportingUnitAmountOfFairValueInExcessOfCarryingAmount_813619" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_GoodwillAndIntangibleAssetsDisclosureLineItems_1017" xlink:to="loc_us-gaap_ReportingUnitAmountOfFairValueInExcessOfCarryingAmount_813619" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_813628" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_GoodwillAndIntangibleAssetsDisclosureLineItems_1017" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_813628" use="optional" order="19" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ChangesInCarryingAmountOfGoodwillBySegmentDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillLineItems" xlink:label="loc_us-gaap_GoodwillLineItems_1041" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_GoodwillAdjustmentsAcquiredDuringPeriod" xlink:label="loc_ter_GoodwillAdjustmentsAcquiredDuringPeriod_1048" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_1041" xlink:to="loc_ter_GoodwillAdjustmentsAcquiredDuringPeriod_1048" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfGoodwillTable" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_1043" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_1041" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_1043" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1042" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_1043" xlink:to="loc_dei_LegalEntityAxis_1042" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1054" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1042" xlink:to="loc_dei_EntityDomain_1054" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1054_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1042" xlink:to="loc_dei_EntityDomain_1054_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_1040" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_1043" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_1040" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1039" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_1040" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1039" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1039_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_1040" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1039_default" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_AutoguideLlcMember" xlink:label="loc_ter_AutoguideLlcMember_677563" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1039" xlink:to="loc_ter_AutoguideLlcMember_677563" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_1045" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_1043" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_1045" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_1044" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_1045" xlink:to="loc_us-gaap_SegmentDomain_1044" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_1044_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_1045" xlink:to="loc_us-gaap_SegmentDomain_1044_default" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SemiconductorTestMember" xlink:label="loc_ter_SemiconductorTestMember_1057" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_1044" xlink:to="loc_ter_SemiconductorTestMember_1057" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SystemsTestGroupMember" xlink:label="loc_ter_SystemsTestGroupMember_1058" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_1044" xlink:to="loc_ter_SystemsTestGroupMember_1058" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_WirelessTestMember" xlink:label="loc_ter_WirelessTestMember_1056" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_1044" xlink:to="loc_ter_WirelessTestMember_1056" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_IndustrialAutomationMember" xlink:label="loc_ter_IndustrialAutomationMember_1055" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_1044" xlink:to="loc_ter_IndustrialAutomationMember_1055" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillForeignCurrencyTranslationGainLoss" xlink:label="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_1049" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_1041" xlink:to="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_1049" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillGross" xlink:label="loc_us-gaap_GoodwillGross_1051" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_1041" xlink:to="loc_us-gaap_GoodwillGross_1051" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillImpairedAccumulatedImpairmentLoss" xlink:label="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_1052" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_1041" xlink:to="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_1052" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_1053" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_1041" xlink:to="loc_us-gaap_Goodwill_1053" use="optional" order="20" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfAmortizableIntangibleAssetsDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_1062" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_1067" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_1062" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_1067" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_1066" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_1062" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_1066" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss_1068" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_1062" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss_1068" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_1069" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_1062" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_1069" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_1065" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_1062" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_1065" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_1061" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_1065" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_1061" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_1063" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_1061" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_1063" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_1063_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_1061" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_1063_default" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TrademarksAndTradeNamesMember" xlink:label="loc_us-gaap_TrademarksAndTradeNamesMember_1072" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_1063" xlink:to="loc_us-gaap_TrademarksAndTradeNamesMember_1072" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="loc_us-gaap_CustomerRelationshipsMember_1071" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_1063" xlink:to="loc_us-gaap_CustomerRelationshipsMember_1071" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DevelopedTechnologyRightsMember" xlink:label="loc_us-gaap_DevelopedTechnologyRightsMember_1070" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_1063" xlink:to="loc_us-gaap_DevelopedTechnologyRightsMember_1070" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_BacklogMember" xlink:label="loc_ter_BacklogMember_321712" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_1063" xlink:to="loc_ter_BacklogMember_321712" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1064" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_1065" xlink:to="loc_dei_LegalEntityAxis_1064" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1074" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1064" xlink:to="loc_dei_EntityDomain_1074" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1074_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1064" xlink:to="loc_dei_EntityDomain_1074_default" use="optional" order="15" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfAmortizableIntangibleAssetsParentheticalDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_1079" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_1081" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_1079" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_1081" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_1078" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_1081" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_1078" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1077" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_1078" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1077" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1077_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_1078" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1077_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ChangeInAccountingEstimateByTypeAxis" xlink:label="loc_us-gaap_ChangeInAccountingEstimateByTypeAxis_321852" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_1081" xlink:to="loc_us-gaap_ChangeInAccountingEstimateByTypeAxis_321852" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ChangeInAccountingEstimateTypeDomain" xlink:label="loc_us-gaap_ChangeInAccountingEstimateTypeDomain_321853" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ChangeInAccountingEstimateByTypeAxis_321852" xlink:to="loc_us-gaap_ChangeInAccountingEstimateTypeDomain_321853" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ChangeInAccountingEstimateTypeDomain" xlink:label="loc_us-gaap_ChangeInAccountingEstimateTypeDomain_321853_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ChangeInAccountingEstimateByTypeAxis_321852" xlink:to="loc_us-gaap_ChangeInAccountingEstimateTypeDomain_321853_default" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1080" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_1081" xlink:to="loc_dei_LegalEntityAxis_1080" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1086" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1080" xlink:to="loc_dei_EntityDomain_1086" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1086_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1080" xlink:to="loc_dei_EntityDomain_1086_default" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ImpairmentOfIntangibleAssetsFinitelived" xlink:label="loc_us-gaap_ImpairmentOfIntangibleAssetsFinitelived_1085" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_1079" xlink:to="loc_us-gaap_ImpairmentOfIntangibleAssetsFinitelived_1085" use="optional" order="11" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfEstimatedIntangibleAssetAmortizationExpenseDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_1089" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_1096" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_1089" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_1096" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_1095" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_1089" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_1095" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_1091" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_1089" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_1091" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1090" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_1091" xlink:to="loc_dei_LegalEntityAxis_1090" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1098" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1090" xlink:to="loc_dei_EntityDomain_1098" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1098_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1090" xlink:to="loc_dei_EntityDomain_1098_default" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_1092" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_1089" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_1092" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_1093" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_1089" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_1093" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_1094" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_1089" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_1094" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive_1097" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_1089" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive_1097" use="optional" order="10" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/CommitmentsAndContingenciesAdditionalInformationDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PurchaseCommitmentExcludingLongtermCommitmentLineItems" xlink:label="loc_us-gaap_PurchaseCommitmentExcludingLongtermCommitmentLineItems_1102" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ExtendedProductWarrantyAccrualPeriodIncreaseDecrease" xlink:label="loc_us-gaap_ExtendedProductWarrantyAccrualPeriodIncreaseDecrease_1110" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PurchaseCommitmentExcludingLongtermCommitmentLineItems_1102" xlink:to="loc_us-gaap_ExtendedProductWarrantyAccrualPeriodIncreaseDecrease_1110" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProductWarrantyAccrualPeriodIncreaseDecrease" xlink:label="loc_us-gaap_ProductWarrantyAccrualPeriodIncreaseDecrease_1109" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PurchaseCommitmentExcludingLongtermCommitmentLineItems_1102" xlink:to="loc_us-gaap_ProductWarrantyAccrualPeriodIncreaseDecrease_1109" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PurchaseCommitmentExcludingLongtermCommitmentTable" xlink:label="loc_us-gaap_PurchaseCommitmentExcludingLongtermCommitmentTable_1103" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PurchaseCommitmentExcludingLongtermCommitmentLineItems_1102" xlink:to="loc_us-gaap_PurchaseCommitmentExcludingLongtermCommitmentTable_1103" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1101" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_PurchaseCommitmentExcludingLongtermCommitmentTable_1103" xlink:to="loc_dei_LegalEntityAxis_1101" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1104" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1101" xlink:to="loc_dei_EntityDomain_1104" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1104_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1101" xlink:to="loc_dei_EntityDomain_1104_default" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PurchaseObligation" xlink:label="loc_us-gaap_PurchaseObligation_1105" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PurchaseCommitmentExcludingLongtermCommitmentLineItems_1102" xlink:to="loc_us-gaap_PurchaseObligation_1105" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PurchaseObligationDueInNextTwelveMonths" xlink:label="loc_us-gaap_PurchaseObligationDueInNextTwelveMonths_1106" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PurchaseCommitmentExcludingLongtermCommitmentLineItems_1102" xlink:to="loc_us-gaap_PurchaseObligationDueInNextTwelveMonths_1106" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_WarrantyPeriod" xlink:label="loc_ter_WarrantyPeriod_1108" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PurchaseCommitmentExcludingLongtermCommitmentLineItems_1102" xlink:to="loc_ter_WarrantyPeriod_1108" use="optional" order="9" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ComputationOfBasicAndDilutedNetIncomePerCommonShareDetail">
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_NetIncomeLossPerCommonShareLineItems" xlink:label="loc_ter_NetIncomeLossPerCommonShareLineItems_1129" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_1138" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_NetIncomeLossPerCommonShareLineItems_1129" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_1138" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EarningsPerShareBasic" xlink:label="loc_us-gaap_EarningsPerShareBasic_1142" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_NetIncomeLossPerCommonShareLineItems_1129" xlink:to="loc_us-gaap_EarningsPerShareBasic_1142" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncrementalCommonSharesAttributableToCallOptionsAndWarrants" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToCallOptionsAndWarrants_1137" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_NetIncomeLossPerCommonShareLineItems_1129" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToCallOptionsAndWarrants_1137" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncrementalCommonSharesAttributableToConversionOfDebtSecurities" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToConversionOfDebtSecurities_1136" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_NetIncomeLossPerCommonShareLineItems_1129" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToConversionOfDebtSecurities_1136" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncrementalCommonSharesAttributableToEquityUnitPurchaseAgreements" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToEquityUnitPurchaseAgreements_1139" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_NetIncomeLossPerCommonShareLineItems_1129" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToEquityUnitPurchaseAgreements_1139" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_1134" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_NetIncomeLossPerCommonShareLineItems_1129" xlink:to="loc_us-gaap_NetIncomeLoss_1134" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment" xlink:label="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment_1140" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_NetIncomeLossPerCommonShareLineItems_1129" xlink:to="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment_1140" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_1141" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_NetIncomeLossPerCommonShareLineItems_1129" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_1141" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="loc_us-gaap_EarningsPerShareDiluted_1143" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_NetIncomeLossPerCommonShareLineItems_1129" xlink:to="loc_us-gaap_EarningsPerShareDiluted_1143" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_1135" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_NetIncomeLossPerCommonShareLineItems_1129" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_1135" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ScheduleOfNetIncomeLossPerCommonShareTable" xlink:label="loc_ter_ScheduleOfNetIncomeLossPerCommonShareTable_1130" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ter_NetIncomeLossPerCommonShareLineItems_1129" xlink:to="loc_ter_ScheduleOfNetIncomeLossPerCommonShareTable_1130" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1128" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_ScheduleOfNetIncomeLossPerCommonShareTable_1130" xlink:to="loc_dei_LegalEntityAxis_1128" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1133" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1128" xlink:to="loc_dei_EntityDomain_1133" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1133_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1128" xlink:to="loc_dei_EntityDomain_1133_default" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_1126" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_ScheduleOfNetIncomeLossPerCommonShareTable_1130" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_1126" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_1127" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_1126" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_1127" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_1127_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_1126" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_1127_default" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_1131" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_1127" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_1131" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_1132" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_1127" xlink:to="loc_us-gaap_EmployeeStockOptionMember_1132" use="optional" order="19" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ComputationOfBasicAndDilutedNetIncomePerCommonShareParentheticalDetail">
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_NetIncomeLossPerCommonShareLineItems" xlink:label="loc_ter_NetIncomeLossPerCommonShareLineItems_1149" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentConvertibleConversionPrice1" xlink:label="loc_us-gaap_DebtInstrumentConvertibleConversionPrice1_1154" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_NetIncomeLossPerCommonShareLineItems_1149" xlink:to="loc_us-gaap_DebtInstrumentConvertibleConversionPrice1_1154" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_AntidilutionAdjustmentsOfConvertibleNoteHedges" xlink:label="loc_ter_AntidilutionAdjustmentsOfConvertibleNoteHedges_1155" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_NetIncomeLossPerCommonShareLineItems_1149" xlink:to="loc_ter_AntidilutionAdjustmentsOfConvertibleNoteHedges_1155" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ScheduleOfNetIncomeLossPerCommonShareTable" xlink:label="loc_ter_ScheduleOfNetIncomeLossPerCommonShareTable_1150" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ter_NetIncomeLossPerCommonShareLineItems_1149" xlink:to="loc_ter_ScheduleOfNetIncomeLossPerCommonShareTable_1150" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1148" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_ScheduleOfNetIncomeLossPerCommonShareTable_1150" xlink:to="loc_dei_LegalEntityAxis_1148" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1153" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1148" xlink:to="loc_dei_EntityDomain_1153" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1153_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1148" xlink:to="loc_dei_EntityDomain_1153_default" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_1146" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_ScheduleOfNetIncomeLossPerCommonShareTable_1150" xlink:to="loc_us-gaap_DebtInstrumentAxis_1146" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_1147" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_1146" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_1147" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_1147_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_1146" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_1147_default" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ConvertibleNoteMember" xlink:label="loc_ter_ConvertibleNoteMember_1151" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_1147" xlink:to="loc_ter_ConvertibleNoteMember_1151" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ConvertibleNotesHedgeAndWarrantMember" xlink:label="loc_ter_ConvertibleNotesHedgeAndWarrantMember_1152" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_1147" xlink:to="loc_ter_ConvertibleNotesHedgeAndWarrantMember_1152" use="optional" order="11" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/NetIncomePerCommonShareAdditionalInformationDetail">
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_NetIncomeLossPerCommonShareLineItems" xlink:label="loc_ter_NetIncomeLossPerCommonShareLineItems_1159" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_StockIssuedDuringPeriodSharesSaleOfStockAndExerciseOfStockOptions" xlink:label="loc_ter_StockIssuedDuringPeriodSharesSaleOfStockAndExerciseOfStockOptions_1162" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_NetIncomeLossPerCommonShareLineItems_1159" xlink:to="loc_ter_StockIssuedDuringPeriodSharesSaleOfStockAndExerciseOfStockOptions_1162" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ScheduleOfNetIncomeLossPerCommonShareTable" xlink:label="loc_ter_ScheduleOfNetIncomeLossPerCommonShareTable_1160" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ter_NetIncomeLossPerCommonShareLineItems_1159" xlink:to="loc_ter_ScheduleOfNetIncomeLossPerCommonShareTable_1160" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1158" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_ScheduleOfNetIncomeLossPerCommonShareTable_1160" xlink:to="loc_dei_LegalEntityAxis_1158" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1161" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1158" xlink:to="loc_dei_EntityDomain_1161" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1161_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1158" xlink:to="loc_dei_EntityDomain_1161_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_331036" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_ScheduleOfNetIncomeLossPerCommonShareTable_1160" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_331036" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_331038" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_331036" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_331038" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_331038_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_331036" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_331038_default" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_331046" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_331038" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_331046" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_516678" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_331038" xlink:to="loc_us-gaap_EmployeeStockOptionMember_516678" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_331032" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_NetIncomeLossPerCommonShareLineItems_1159" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_331032" use="optional" order="11" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/RestructuringAndOtherAdditionalInformationDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringCostAndReserveLineItems" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_1176" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_1193" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_1176" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_1193" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_1190" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_1176" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_1190" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LossOnContractTermination" xlink:label="loc_us-gaap_LossOnContractTermination_718915" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_1176" xlink:to="loc_us-gaap_LossOnContractTermination_718915" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherRestructuringCosts" xlink:label="loc_us-gaap_OtherRestructuringCosts_718916" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_1176" xlink:to="loc_us-gaap_OtherRestructuringCosts_718916" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_1177" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_1176" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_1177" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueByAssetClassAxis" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_1169" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_1177" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_1169" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_1168" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_1169" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_1168" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_1168_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_1169" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_1168_default" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_1166" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_1177" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_1166" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1165" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_1166" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1165" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1165_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_1166" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1165_default" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_MobileIndustrialRobotsApsMember" xlink:label="loc_ter_MobileIndustrialRobotsApsMember_1182" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1165" xlink:to="loc_ter_MobileIndustrialRobotsApsMember_1182" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_UniversalRobotsMember" xlink:label="loc_ter_UniversalRobotsMember_1180" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1165" xlink:to="loc_ter_UniversalRobotsMember_1180" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1170" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_1177" xlink:to="loc_dei_LegalEntityAxis_1170" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1185" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1170" xlink:to="loc_dei_EntityDomain_1185" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1185_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1170" xlink:to="loc_dei_EntityDomain_1185_default" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LiabilityForCatastropheClaimsByCatastrophicEventAxis" xlink:label="loc_us-gaap_LiabilityForCatastropheClaimsByCatastrophicEventAxis_1171" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_1177" xlink:to="loc_us-gaap_LiabilityForCatastropheClaimsByCatastrophicEventAxis_1171" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CatastrophicEventDomain" xlink:label="loc_us-gaap_CatastrophicEventDomain_1167" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LiabilityForCatastropheClaimsByCatastrophicEventAxis_1171" xlink:to="loc_us-gaap_CatastrophicEventDomain_1167" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CatastrophicEventDomain" xlink:label="loc_us-gaap_CatastrophicEventDomain_1167_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LiabilityForCatastropheClaimsByCatastrophicEventAxis_1171" xlink:to="loc_us-gaap_CatastrophicEventDomain_1167_default" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_1172" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_1177" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_1172" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LossContingencyNatureDomain" xlink:label="loc_us-gaap_LossContingencyNatureDomain_1173" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_1172" xlink:to="loc_us-gaap_LossContingencyNatureDomain_1173" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LossContingencyNatureDomain" xlink:label="loc_us-gaap_LossContingencyNatureDomain_1173_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_1172" xlink:to="loc_us-gaap_LossContingencyNatureDomain_1173_default" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductOrServiceAxis" xlink:label="loc_srt_ProductOrServiceAxis_1174" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_1177" xlink:to="loc_srt_ProductOrServiceAxis_1174" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_1175" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_1174" xlink:to="loc_srt_ProductsAndServicesDomain_1175" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_1175_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_1174" xlink:to="loc_srt_ProductsAndServicesDomain_1175_default" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_TerCorporateAndEliminationsMember" xlink:label="loc_ter_TerCorporateAndEliminationsMember_718917" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_1175" xlink:to="loc_ter_TerCorporateAndEliminationsMember_718917" use="optional" order="26" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SemiconductorTestIndustrialAutomationAndCorporateMember" xlink:label="loc_ter_SemiconductorTestIndustrialAutomationAndCorporateMember_1189" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_1175" xlink:to="loc_ter_SemiconductorTestIndustrialAutomationAndCorporateMember_1189" use="optional" order="27" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_1179" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_1177" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_1179" use="optional" order="28" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_1178" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_1179" xlink:to="loc_us-gaap_SegmentDomain_1178" use="optional" order="29" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_1178_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_1179" xlink:to="loc_us-gaap_SegmentDomain_1178_default" use="optional" order="30" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_AutoguideMember" xlink:label="loc_ter_AutoguideMember_813653" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_1178" xlink:to="loc_ter_AutoguideMember_813653" use="optional" order="31" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SemiconductorTestMember" xlink:label="loc_ter_SemiconductorTestMember_1199" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_1178" xlink:to="loc_ter_SemiconductorTestMember_1199" use="optional" order="32" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SeveranceCosts1" xlink:label="loc_us-gaap_SeveranceCosts1_1191" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_1176" xlink:to="loc_us-gaap_SeveranceCosts1_1191" use="optional" order="33" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/RetirementPlansAdditionalInformationDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1204" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation" xlink:label="loc_us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation_1217" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1204" xlink:to="loc_us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation_1217" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate_1219" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1204" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate_1219" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear_1223" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1204" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear_1223" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets_1218" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1204" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets_1218" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligationPeriodIncreaseDecrease" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligationPeriodIncreaseDecrease_1214" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1204" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligationPeriodIncreaseDecrease_1214" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanContributionsByEmployer" xlink:label="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_1222" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1204" xlink:to="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_1222" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_1220" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1204" xlink:to="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_1220" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1" xlink:label="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1_1216" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1204" xlink:to="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1_1216" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsPeriodIncreaseDecrease" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsPeriodIncreaseDecrease_1215" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1204" xlink:to="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsPeriodIncreaseDecrease_1215" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DefinedBenefitPlanNumberOfRetireeParticipantsWhoHadDeferredVestedBenefitsTransferredToInsurance" xlink:label="loc_ter_DefinedBenefitPlanNumberOfRetireeParticipantsWhoHadDeferredVestedBenefitsTransferredToInsurance_1213" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1204" xlink:to="loc_ter_DefinedBenefitPlanNumberOfRetireeParticipantsWhoHadDeferredVestedBenefitsTransferredToInsurance_1213" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1212" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1204" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1212" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1205" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1212" xlink:to="loc_dei_LegalEntityAxis_1205" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1225" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1205" xlink:to="loc_dei_EntityDomain_1225" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1225_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1205" xlink:to="loc_dei_EntityDomain_1225_default" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameAxis" xlink:label="loc_us-gaap_RetirementPlanNameAxis_1206" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1212" xlink:to="loc_us-gaap_RetirementPlanNameAxis_1206" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameDomain" xlink:label="loc_us-gaap_RetirementPlanNameDomain_1207" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanNameAxis_1206" xlink:to="loc_us-gaap_RetirementPlanNameDomain_1207" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameDomain" xlink:label="loc_us-gaap_RetirementPlanNameDomain_1207_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanNameAxis_1206" xlink:to="loc_us-gaap_RetirementPlanNameDomain_1207_default" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_NonUSSubsidiariesMember" xlink:label="loc_ter_NonUSSubsidiariesMember_1228" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_1207" xlink:to="loc_ter_NonUSSubsidiariesMember_1228" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_UnitedStatesPlansMember" xlink:label="loc_ter_UnitedStatesPlansMember_1226" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_1207" xlink:to="loc_ter_UnitedStatesPlansMember_1226" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_UnitedStatesSupplementalExecutiveDefinedBenefitPensionPlanMember" xlink:label="loc_ter_UnitedStatesSupplementalExecutiveDefinedBenefitPensionPlanMember_1227" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_1207" xlink:to="loc_ter_UnitedStatesSupplementalExecutiveDefinedBenefitPensionPlanMember_1227" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_TaiwanPlanMember" xlink:label="loc_ter_TaiwanPlanMember_1229" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_1207" xlink:to="loc_ter_TaiwanPlanMember_1229" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_PensionPlanOneAxis" xlink:label="loc_ter_PensionPlanOneAxis_763887" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1212" xlink:to="loc_ter_PensionPlanOneAxis_763887" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_PensionPlanOneDomain" xlink:label="loc_ter_PensionPlanOneDomain_763888" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_ter_PensionPlanOneAxis_763887" xlink:to="loc_ter_PensionPlanOneDomain_763888" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_PensionPlanOneDomain" xlink:label="loc_ter_PensionPlanOneDomain_763888_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_ter_PensionPlanOneAxis_763887" xlink:to="loc_ter_PensionPlanOneDomain_763888_default" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_1210" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1212" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_1210" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_1211" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_1210" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_1211" use="optional" order="26" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_1211_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_1210" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_1211_default" use="optional" order="27" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_1232" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_1211" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_1232" use="optional" order="28" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_815039" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1212" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_815039" use="optional" order="29" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_815040" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_815039" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_815040" use="optional" order="30" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_815040_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_815039" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_815040_default" use="optional" order="31" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US" xlink:label="loc_country_US_815043" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_815040" xlink:to="loc_country_US_815043" use="optional" order="32" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignPlanMember" xlink:label="loc_us-gaap_ForeignPlanMember_815044" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_815040" xlink:to="loc_us-gaap_ForeignPlanMember_815044" use="optional" order="33" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanActuarialGainLoss" xlink:label="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss_825899" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1204" xlink:to="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss_825899" use="optional" order="34" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfDefinedBenefitPensionAndPostretirementBenefitPlanAssetsAndObligationDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1235" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets" xlink:label="loc_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_1256" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1235" xlink:to="loc_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_1256" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DefinedBenefitPlanAssetsRetireeAnnuityPurchase" xlink:label="loc_ter_DefinedBenefitPlanAssetsRetireeAnnuityPurchase_1258" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1235" xlink:to="loc_ter_DefinedBenefitPlanAssetsRetireeAnnuityPurchase_1258" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligation" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligation_1242" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1235" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligation_1242" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanActuarialGainLoss" xlink:label="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss_1245" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1235" xlink:to="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss_1245" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_1247" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1235" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_1247" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_1254" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1235" xlink:to="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_1254" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation" xlink:label="loc_us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation_1252" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1235" xlink:to="loc_us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation_1252" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanInterestCost" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_1244" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1235" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_1244" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid_1257" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1235" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid_1257" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DefinedBenefitPlanBenefitObligationRetireeAnnuityPurchase" xlink:label="loc_ter_DefinedBenefitPlanBenefitObligationRetireeAnnuityPurchase_1248" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1235" xlink:to="loc_ter_DefinedBenefitPlanBenefitObligationRetireeAnnuityPurchase_1248" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanContributionsByEmployer" xlink:label="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_1255" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1235" xlink:to="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_1255" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss_1261" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1235" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss_1261" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanServiceCost" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_1243" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1235" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_1243" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanFundedStatusOfPlan" xlink:label="loc_us-gaap_DefinedBenefitPlanFundedStatusOfPlan_1263" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1235" xlink:to="loc_us-gaap_DefinedBenefitPlanFundedStatusOfPlan_1263" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DefinedBenefitPlanBenefitObligationSettlementLiabilityLoss" xlink:label="loc_ter_DefinedBenefitPlanBenefitObligationSettlementLiabilityLoss_1249" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1235" xlink:to="loc_ter_DefinedBenefitPlanBenefitObligationSettlementLiabilityLoss_1249" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1241" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1235" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1241" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1236" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1241" xlink:to="loc_dei_LegalEntityAxis_1236" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1264" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1236" xlink:to="loc_dei_EntityDomain_1264" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1264_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1236" xlink:to="loc_dei_EntityDomain_1264_default" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_1239" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1241" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_1239" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_1240" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_1239" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_1240" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_1240_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_1239" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_1240_default" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_1267" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_1240" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_1267" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_1237" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1241" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_1237" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_1238" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1237" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_1238" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_1238_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1237" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_1238_default" use="optional" order="26" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignPlanMember" xlink:label="loc_us-gaap_ForeignPlanMember_1266" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_1238" xlink:to="loc_us-gaap_ForeignPlanMember_1266" use="optional" order="27" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US" xlink:label="loc_country_US_1265" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_1238" xlink:to="loc_country_US_1265" use="optional" order="28" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfAmountsRecordedWithinStatementsOfFinancialPositionDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_819248" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanFundedStatusOfPlan" xlink:label="loc_us-gaap_DefinedBenefitPlanFundedStatusOfPlan_1280" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_819248" xlink:to="loc_us-gaap_DefinedBenefitPlanFundedStatusOfPlan_1280" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_PensionAndOtherPostretirementDefinedBenefitPlansAccruedEmployeesCompensationAndWithholdingsCurrentAndNoncurrent" xlink:label="loc_ter_PensionAndOtherPostretirementDefinedBenefitPlansAccruedEmployeesCompensationAndWithholdingsCurrentAndNoncurrent_1278" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_819248" xlink:to="loc_ter_PensionAndOtherPostretirementDefinedBenefitPlansAccruedEmployeesCompensationAndWithholdingsCurrentAndNoncurrent_1278" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent" xlink:label="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent_1279" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_819248" xlink:to="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent_1279" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent" xlink:label="loc_us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent_1277" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_819248" xlink:to="loc_us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent_1277" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_819245" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_819248" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_819245" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_819251" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_819245" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_819251" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_819252" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_819251" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_819252" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_819252_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_819251" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_819252_default" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_1284" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_819252" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_1284" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_819253" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_819245" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_819253" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_819254" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_819253" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_819254" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_819254_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_819253" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_819254_default" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US" xlink:label="loc_country_US_1282" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_819254" xlink:to="loc_country_US_1282" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignPlanMember" xlink:label="loc_us-gaap_ForeignPlanMember_1283" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_819254" xlink:to="loc_us-gaap_ForeignPlanMember_1283" use="optional" order="14" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfAmountsRecognizedInAccumulatedOtherComprehensiveIncomeDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1287" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostCreditArisingDuringPeriodBeforeTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostCreditArisingDuringPeriodBeforeTax_1294" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1287" xlink:to="loc_us-gaap_OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostCreditArisingDuringPeriodBeforeTax_1294" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent" xlink:label="loc_us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent_1296" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1287" xlink:to="loc_us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent_1296" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax_1295" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1287" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax_1295" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1293" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1287" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1293" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1288" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1293" xlink:to="loc_dei_LegalEntityAxis_1288" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1297" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1288" xlink:to="loc_dei_EntityDomain_1297" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1297_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1288" xlink:to="loc_dei_EntityDomain_1297_default" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_1289" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1293" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_1289" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_1290" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1289" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_1290" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_1290_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1289" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_1290_default" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignPlanMember" xlink:label="loc_us-gaap_ForeignPlanMember_1299" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_1290" xlink:to="loc_us-gaap_ForeignPlanMember_1299" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US" xlink:label="loc_country_US_1298" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_1290" xlink:to="loc_country_US_1298" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_1291" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1293" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_1291" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_1292" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_1291" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_1292" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_1292_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_1291" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_1292_default" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_1300" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_1292" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_1300" use="optional" order="16" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfPensionPlansWithAccumulatedBenefitObligationAndProjectedBenefitObligationInExcessOfPlanAssetsDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1303" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateProjectedBenefitObligation" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateProjectedBenefitObligation_1308" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1303" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateProjectedBenefitObligation_1308" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation_1309" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1303" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation_1309" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets_1310" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1303" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets_1310" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1307" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1303" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1307" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1304" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1307" xlink:to="loc_dei_LegalEntityAxis_1304" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1311" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1304" xlink:to="loc_dei_EntityDomain_1311" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1311_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1304" xlink:to="loc_dei_EntityDomain_1311_default" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_1305" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1307" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_1305" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_1306" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1305" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_1306" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_1306_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1305" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_1306_default" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignPlanMember" xlink:label="loc_us-gaap_ForeignPlanMember_1313" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_1306" xlink:to="loc_us-gaap_ForeignPlanMember_1313" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US" xlink:label="loc_country_US_1312" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_1306" xlink:to="loc_country_US_1312" use="optional" order="12" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfNetPeriodicPensionAndPostretirementIncomeCostDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1316" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_1327" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1316" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_1327" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanServiceCost" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_1323" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1316" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_1323" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanSpecialTerminationBenefits" xlink:label="loc_us-gaap_DefinedBenefitPlanSpecialTerminationBenefits_1329" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1316" xlink:to="loc_us-gaap_DefinedBenefitPlanSpecialTerminationBenefits_1329" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_1325" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1316" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_1325" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanInterestCost" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_1324" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1316" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_1324" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments" xlink:label="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments_1328" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1316" xlink:to="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments_1328" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_499624" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1316" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_499624" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_1326" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1316" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_1326" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1322" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1316" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1322" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_1320" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1322" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_1320" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_1321" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_1320" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_1321" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_1321_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_1320" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_1321_default" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_1339" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_1321" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_1339" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_1318" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1322" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_1318" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_1319" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1318" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_1319" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_1319_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1318" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_1319_default" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US" xlink:label="loc_country_US_1337" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_1319" xlink:to="loc_country_US_1337" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignPlanMember" xlink:label="loc_us-gaap_ForeignPlanMember_1338" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_1319" xlink:to="loc_us-gaap_ForeignPlanMember_1338" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1317" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1322" xlink:to="loc_dei_LegalEntityAxis_1317" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1336" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1317" xlink:to="loc_dei_EntityDomain_1336" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1336_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1317" xlink:to="loc_dei_EntityDomain_1336_default" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax" xlink:label="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax_814862" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1316" xlink:to="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax_814862" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax_814866" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1316" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax_814866" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AmountRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveIncomeLossBeforeTax" xlink:label="loc_us-gaap_AmountRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveIncomeLossBeforeTax_814869" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1316" xlink:to="loc_us-gaap_AmountRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveIncomeLossBeforeTax_814869" use="optional" order="24" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfWeightedAverageAssumptionsToDetermineNetPeriodicPensionCostDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1342" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1348" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1342" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1348" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_1346" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1348" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_1346" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_1347" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_1346" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_1347" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_1347_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_1346" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_1347_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_1358" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_1347" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_1358" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1343" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1348" xlink:to="loc_dei_LegalEntityAxis_1343" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1355" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1343" xlink:to="loc_dei_EntityDomain_1355" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1355_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1343" xlink:to="loc_dei_EntityDomain_1355_default" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_1344" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1348" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_1344" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_1345" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1344" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_1345" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_1345_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1344" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_1345_default" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignPlanMember" xlink:label="loc_us-gaap_ForeignPlanMember_1357" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_1345" xlink:to="loc_us-gaap_ForeignPlanMember_1357" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US" xlink:label="loc_country_US_1356" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_1345" xlink:to="loc_country_US_1356" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanYearHealthCareCostTrendRateReachesUltimateTrendRate" xlink:label="loc_us-gaap_DefinedBenefitPlanYearHealthCareCostTrendRateReachesUltimateTrendRate_1354" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1342" xlink:to="loc_us-gaap_DefinedBenefitPlanYearHealthCareCostTrendRateReachesUltimateTrendRate_1354" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_1349" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1342" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_1349" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease_1353" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1342" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease_1353" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets_1351" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1342" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets_1351" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear" xlink:label="loc_us-gaap_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear_1350" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1342" xlink:to="loc_us-gaap_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear_1350" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanUltimateHealthCareCostTrendRate1" xlink:label="loc_us-gaap_DefinedBenefitPlanUltimateHealthCareCostTrendRate1_1352" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1342" xlink:to="loc_us-gaap_DefinedBenefitPlanUltimateHealthCareCostTrendRate1_1352" use="optional" order="19" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfWeightedAverageAssumptionsToDeterminePensionObligationsDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1361" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanUltimateHealthCareCostTrendRate1" xlink:label="loc_us-gaap_DefinedBenefitPlanUltimateHealthCareCostTrendRate1_1371" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1361" xlink:to="loc_us-gaap_DefinedBenefitPlanUltimateHealthCareCostTrendRate1_1371" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationInitialMedicalTrend" xlink:label="loc_ter_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationInitialMedicalTrend_1369" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1361" xlink:to="loc_ter_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationInitialMedicalTrend_1369" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate_1368" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1361" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate_1368" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationMedicalCostTrendRateDecreaseToUltimateRateInYear" xlink:label="loc_ter_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationMedicalCostTrendRateDecreaseToUltimateRateInYear_1372" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1361" xlink:to="loc_ter_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationMedicalCostTrendRateDecreaseToUltimateRateInYear_1372" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationSalaryProgressionRate" xlink:label="loc_ter_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationSalaryProgressionRate_1370" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1361" xlink:to="loc_ter_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationSalaryProgressionRate_1370" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1367" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1361" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1367" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1362" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1367" xlink:to="loc_dei_LegalEntityAxis_1362" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1373" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1362" xlink:to="loc_dei_EntityDomain_1373" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1373_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1362" xlink:to="loc_dei_EntityDomain_1373_default" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_1363" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1367" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_1363" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_1364" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1363" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_1364" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_1364_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1363" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_1364_default" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignPlanMember" xlink:label="loc_us-gaap_ForeignPlanMember_1375" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_1364" xlink:to="loc_us-gaap_ForeignPlanMember_1375" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US" xlink:label="loc_country_US_1374" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_1364" xlink:to="loc_country_US_1374" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_1365" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1367" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_1365" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_1366" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_1365" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_1366" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_1366_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_1365" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_1366_default" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_1376" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_1366" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_1376" use="optional" order="18" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfWeightedAveragePensionAssetsAllocationsByCategoryDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1380" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations" xlink:label="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations_1386" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1380" xlink:to="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations_1386" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1385" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1380" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1385" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_1379" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1385" xlink:to="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_1379" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanAssetCategoriesDomain" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_1382" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_1379" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_1382" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanAssetCategoriesDomain" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_1382_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_1379" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_1382_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FixedIncomeSecuritiesMember" xlink:label="loc_us-gaap_FixedIncomeSecuritiesMember_1388" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_1382" xlink:to="loc_us-gaap_FixedIncomeSecuritiesMember_1388" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquitySecuritiesMember" xlink:label="loc_us-gaap_EquitySecuritiesMember_1389" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_1382" xlink:to="loc_us-gaap_EquitySecuritiesMember_1389" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherThanSecuritiesInvestmentMember" xlink:label="loc_us-gaap_OtherThanSecuritiesInvestmentMember_1390" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_1382" xlink:to="loc_us-gaap_OtherThanSecuritiesInvestmentMember_1390" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_1383" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1385" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_1383" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_1384" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1383" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_1384" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_1384_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1383" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_1384_default" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignPlanMember" xlink:label="loc_us-gaap_ForeignPlanMember_1392" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_1384" xlink:to="loc_us-gaap_ForeignPlanMember_1392" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US" xlink:label="loc_country_US_1391" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_1384" xlink:to="loc_country_US_1391" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1381" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1385" xlink:to="loc_dei_LegalEntityAxis_1381" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1387" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1381" xlink:to="loc_dei_EntityDomain_1387" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1387_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1381" xlink:to="loc_dei_EntityDomain_1387_default" use="optional" order="16" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfTargetAssetsAllocationDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1396" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage_1402" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1396" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage_1402" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1401" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1396" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1401" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_1395" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1401" xlink:to="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_1395" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanAssetCategoriesDomain" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_1400" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_1395" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_1400" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanAssetCategoriesDomain" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_1400_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_1395" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_1400_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_UsGovernmentFixedIncomeMember" xlink:label="loc_ter_UsGovernmentFixedIncomeMember_1411" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_1400" xlink:to="loc_ter_UsGovernmentFixedIncomeMember_1411" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashMember" xlink:label="loc_us-gaap_CashMember_1413" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_1400" xlink:to="loc_us-gaap_CashMember_1413" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_GlobalEquitySecuritiesMember" xlink:label="loc_ter_GlobalEquitySecuritiesMember_1410" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_1400" xlink:to="loc_ter_GlobalEquitySecuritiesMember_1410" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_HighYieldFixedIncomeMember" xlink:label="loc_ter_HighYieldFixedIncomeMember_1412" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_1400" xlink:to="loc_ter_HighYieldFixedIncomeMember_1412" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_USCorporateFixedIncomeMember" xlink:label="loc_ter_USCorporateFixedIncomeMember_1409" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_1400" xlink:to="loc_ter_USCorporateFixedIncomeMember_1409" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentTypeAxis" xlink:label="loc_us-gaap_InvestmentTypeAxis_1397" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1401" xlink:to="loc_us-gaap_InvestmentTypeAxis_1397" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_1398" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_1397" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_1398" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_1398_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_1397" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_1398_default" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_BloombergBarclaysCorporateAOrBetterIndexMember" xlink:label="loc_ter_BloombergBarclaysCorporateAOrBetterIndexMember_1403" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_1398" xlink:to="loc_ter_BloombergBarclaysCorporateAOrBetterIndexMember_1403" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_BloombergBarclaysCorporateHighYieldIssuerCapIndexMember" xlink:label="loc_ter_BloombergBarclaysCorporateHighYieldIssuerCapIndexMember_1406" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_1398" xlink:to="loc_ter_BloombergBarclaysCorporateHighYieldIssuerCapIndexMember_1406" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_MsciWorldMinimumVolatilityIndexMember" xlink:label="loc_ter_MsciWorldMinimumVolatilityIndexMember_1404" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_1398" xlink:to="loc_ter_MsciWorldMinimumVolatilityIndexMember_1404" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_CitiGroupThreeMonthTreasuryBillIndexMember" xlink:label="loc_ter_CitiGroupThreeMonthTreasuryBillIndexMember_1407" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_1398" xlink:to="loc_ter_CitiGroupThreeMonthTreasuryBillIndexMember_1407" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_BloombergBarclaysLongGovernmentBondIndexMember" xlink:label="loc_ter_BloombergBarclaysLongGovernmentBondIndexMember_1405" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_1398" xlink:to="loc_ter_BloombergBarclaysLongGovernmentBondIndexMember_1405" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1399" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1401" xlink:to="loc_dei_LegalEntityAxis_1399" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1408" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1399" xlink:to="loc_dei_EntityDomain_1408" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1408_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1399" xlink:to="loc_dei_EntityDomain_1408_default" use="optional" order="21" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfFairValueOfPensionsPlanAssetsByAssetCategoryDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1417" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_1425" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1417" xlink:to="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_1425" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1424" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1417" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1424" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_1418" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1424" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_1418" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1419" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_1418" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1419" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1419_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_1418" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1419_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_1426" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1419" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_1426" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_1427" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1419" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_1427" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_1428" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1419" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_1428" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_1416" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1424" xlink:to="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_1416" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanAssetCategoriesDomain" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_1421" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_1416" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_1421" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanAssetCategoriesDomain" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_1421_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_1416" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_1421_default" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_USGovernmentDebtSecuritiesMember" xlink:label="loc_us-gaap_USGovernmentDebtSecuritiesMember_1431" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_1421" xlink:to="loc_us-gaap_USGovernmentDebtSecuritiesMember_1431" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CorporateDebtSecuritiesMember" xlink:label="loc_us-gaap_CorporateDebtSecuritiesMember_1430" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_1421" xlink:to="loc_us-gaap_CorporateDebtSecuritiesMember_1430" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashAndCashEquivalentsMember" xlink:label="loc_us-gaap_CashAndCashEquivalentsMember_1434" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_1421" xlink:to="loc_us-gaap_CashAndCashEquivalentsMember_1434" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_GlobalEquitySecuritiesMember" xlink:label="loc_ter_GlobalEquitySecuritiesMember_1432" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_1421" xlink:to="loc_ter_GlobalEquitySecuritiesMember_1432" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherCreditDerivativesMember" xlink:label="loc_us-gaap_OtherCreditDerivativesMember_1433" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_1421" xlink:to="loc_us-gaap_OtherCreditDerivativesMember_1433" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_1422" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1424" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_1422" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_1423" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1422" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_1423" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_1423_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1422" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_1423_default" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US" xlink:label="loc_country_US_1436" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_1423" xlink:to="loc_country_US_1436" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignPlanMember" xlink:label="loc_us-gaap_ForeignPlanMember_1437" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_1423" xlink:to="loc_us-gaap_ForeignPlanMember_1437" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1420" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1424" xlink:to="loc_dei_LegalEntityAxis_1420" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1429" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1420" xlink:to="loc_dei_EntityDomain_1429" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1429_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1420" xlink:to="loc_dei_EntityDomain_1429_default" use="optional" order="24" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfExpectedFutureBenefitPaymentsDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1461" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_1470" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1461" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_1470" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_1468" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1461" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_1468" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_1472" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1461" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_1472" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_1471" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1461" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_1471" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_1469" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1461" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_1469" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter_1473" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1461" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter_1473" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1467" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1461" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1467" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1462" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1467" xlink:to="loc_dei_LegalEntityAxis_1462" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1474" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1462" xlink:to="loc_dei_EntityDomain_1474" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1474_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1462" xlink:to="loc_dei_EntityDomain_1474_default" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_1463" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1467" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_1463" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_1464" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1463" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_1464" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_1464_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1463" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_1464_default" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignPlanMember" xlink:label="loc_us-gaap_ForeignPlanMember_1476" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_1464" xlink:to="loc_us-gaap_ForeignPlanMember_1476" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US" xlink:label="loc_country_US_1475" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_1464" xlink:to="loc_country_US_1475" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_1465" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1467" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_1465" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_1466" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_1465" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_1466" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_1466_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_1465" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_1466_default" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_1477" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_1466" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_1477" use="optional" order="19" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/StockBasedCompensationAdditionalInformationDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DividendsPerShare" xlink:label="loc_ter_DividendsPerShare_1514" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_ter_DividendsPerShare_1514" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_1520" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_1520" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_MaximumSharesCanBePurchasedUnderPlanAtFairMarketValue" xlink:label="loc_ter_MaximumSharesCanBePurchasedUnderPlanAtFairMarketValue_1522" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_ter_MaximumSharesCanBePurchasedUnderPlanAtFairMarketValue_1522" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_1519" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_1519" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_1518" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_1518" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_MinimumRetirementAgeForEligibleEmployeesOfPostretirementPlans" xlink:label="loc_ter_MinimumRetirementAgeForEligibleEmployeesOfPostretirementPlans_1510" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_ter_MinimumRetirementAgeForEligibleEmployeesOfPostretirementPlans_1510" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_MinimumYearsOfServiceForEligibleEmployeesOfPostretirementPlans" xlink:label="loc_ter_MinimumYearsOfServiceForEligibleEmployeesOfPostretirementPlans_1511" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_ter_MinimumYearsOfServiceForEligibleEmployeesOfPostretirementPlans_1511" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="loc_us-gaap_ProceedsFromStockOptionsExercised_1517" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_us-gaap_ProceedsFromStockOptionsExercised_1517" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingPercentageUponOneYearAnniversaryOfDateOfGrant" xlink:label="loc_ter_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingPercentageUponOneYearAnniversaryOfDateOfGrant_1506" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_ter_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingPercentageUponOneYearAnniversaryOfDateOfGrant_1506" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharesIssuedPricePerShare" xlink:label="loc_us-gaap_SharesIssuedPricePerShare_1526" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_us-gaap_SharesIssuedPricePerShare_1526" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumNumberOfSharesPerEmployee" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumNumberOfSharesPerEmployee_1523" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumNumberOfSharesPerEmployee_1523" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_1525" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_1525" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1494" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1494" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_1490" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1494" xlink:to="loc_us-gaap_AwardTypeAxis_1490" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1496" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_1490" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1496" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1496_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_1490" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1496_default" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_1528" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1496" xlink:to="loc_us-gaap_EmployeeStockOptionMember_1528" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_EmployeeStockPurchasePlanMember" xlink:label="loc_ter_EmployeeStockPurchasePlanMember_1531" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1496" xlink:to="loc_ter_EmployeeStockPurchasePlanMember_1531" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ServiceBasedRestrictedStockUnitsMember" xlink:label="loc_ter_ServiceBasedRestrictedStockUnitsMember_1533" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1496" xlink:to="loc_ter_ServiceBasedRestrictedStockUnitsMember_1533" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ProfitBeforeIncomeAndTaxPerformanceBasedRestrictedStockUnitsMember" xlink:label="loc_ter_ProfitBeforeIncomeAndTaxPerformanceBasedRestrictedStockUnitsMember_1532" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1496" xlink:to="loc_ter_ProfitBeforeIncomeAndTaxPerformanceBasedRestrictedStockUnitsMember_1532" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_1529" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1496" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_1529" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_TotalShareholderReturnPerformanceBasedRestrictedStockUnitsMember" xlink:label="loc_ter_TotalShareholderReturnPerformanceBasedRestrictedStockUnitsMember_1530" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1496" xlink:to="loc_ter_TotalShareholderReturnPerformanceBasedRestrictedStockUnitsMember_1530" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1491" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1494" xlink:to="loc_dei_LegalEntityAxis_1491" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1503" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1491" xlink:to="loc_dei_EntityDomain_1503" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1503_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1491" xlink:to="loc_dei_EntityDomain_1503_default" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MeasurementInputTypeAxis" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_1492" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1494" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_1492" use="optional" order="26" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MeasurementInputTypeDomain" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_1493" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_1492" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_1493" use="optional" order="27" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MeasurementInputTypeDomain" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_1493_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_1492" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_1493_default" use="optional" order="28" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MeasurementInputExpectedDividendPaymentMember" xlink:label="loc_us-gaap_MeasurementInputExpectedDividendPaymentMember_1504" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_1493" xlink:to="loc_us-gaap_MeasurementInputExpectedDividendPaymentMember_1504" use="optional" order="29" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_321858" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1494" xlink:to="loc_srt_RangeAxis_321858" use="optional" order="30" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_321859" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_321858" xlink:to="loc_srt_RangeMember_321859" use="optional" order="31" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_321859_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_321858" xlink:to="loc_srt_RangeMember_321859_default" use="optional" order="32" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_321860" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_321859" xlink:to="loc_srt_MinimumMember_321860" use="optional" order="33" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_321861" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_321859" xlink:to="loc_srt_MaximumMember_321861" use="optional" order="34" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_1497" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1494" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_1497" use="optional" order="35" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_1498" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_1497" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_1498" use="optional" order="36" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_1498_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_1497" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_1498_default" use="optional" order="37" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="loc_us-gaap_SubsequentEventMember_1534" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_1498" xlink:to="loc_us-gaap_SubsequentEventMember_1534" use="optional" order="38" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="loc_us-gaap_TypeOfArrangementAxis_498315" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1494" xlink:to="loc_us-gaap_TypeOfArrangementAxis_498315" use="optional" order="39" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_498316" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TypeOfArrangementAxis_498315" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_498316" use="optional" order="40" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_498316_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TypeOfArrangementAxis_498315" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_498316_default" use="optional" order="41" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_RetirementAgreementMember" xlink:label="loc_ter_RetirementAgreementMember_498317" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_498316" xlink:to="loc_ter_RetirementAgreementMember_498317" use="optional" order="42" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VestingAxis" xlink:label="loc_us-gaap_VestingAxis_1501" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1494" xlink:to="loc_us-gaap_VestingAxis_1501" use="optional" order="43" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VestingDomain" xlink:label="loc_us-gaap_VestingDomain_1502" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VestingAxis_1501" xlink:to="loc_us-gaap_VestingDomain_1502" use="optional" order="44" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VestingDomain" xlink:label="loc_us-gaap_VestingDomain_1502_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VestingAxis_1501" xlink:to="loc_us-gaap_VestingDomain_1502_default" use="optional" order="45" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationAwardTrancheOneMember" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheOneMember_1539" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_1502" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheOneMember_1539" use="optional" order="46" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationAwardTrancheTwoMember" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheTwoMember_1540" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_1502" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheTwoMember_1540" use="optional" order="47" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_TitleOfIndividualAxis" xlink:label="loc_srt_TitleOfIndividualAxis_1499" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1494" xlink:to="loc_srt_TitleOfIndividualAxis_1499" use="optional" order="48" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_1500" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_TitleOfIndividualAxis_1499" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_1500" use="optional" order="49" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_1500_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_TitleOfIndividualAxis_1499" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_1500_default" use="optional" order="50" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_EmployeesMember" xlink:label="loc_ter_EmployeesMember_1535" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_1500" xlink:to="loc_ter_EmployeesMember_1535" use="optional" order="51" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ExecutiveOfficerMember" xlink:label="loc_srt_ExecutiveOfficerMember_1538" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_1500" xlink:to="loc_srt_ExecutiveOfficerMember_1538" use="optional" order="52" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_NonEmployeeDirectorsAndCertainEmployeesMember" xlink:label="loc_ter_NonEmployeeDirectorsAndCertainEmployeesMember_1537" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_1500" xlink:to="loc_ter_NonEmployeeDirectorsAndCertainEmployeesMember_1537" use="optional" order="53" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_DirectorMember" xlink:label="loc_srt_DirectorMember_1536" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_1500" xlink:to="loc_srt_DirectorMember_1536" use="optional" order="54" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_1505" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_1505" use="optional" order="55" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_1508" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_1508" use="optional" order="56" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_1512" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_1512" use="optional" order="57" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_1513" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_1513" use="optional" order="58" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDescription" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDescription_1509" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDescription_1509" use="optional" order="59" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_1527" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_1527" use="optional" order="60" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate_1521" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate_1521" use="optional" order="61" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ShareholderReturnAwardPerformanceMeasurementPeriod" xlink:label="loc_ter_ShareholderReturnAwardPerformanceMeasurementPeriod_1507" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_ter_ShareholderReturnAwardPerformanceMeasurementPeriod_1507" use="optional" order="62" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharePrice" xlink:label="loc_us-gaap_SharePrice_1515" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_us-gaap_SharePrice_1515" use="optional" order="63" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent_1524" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent_1524" use="optional" order="64" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_498314" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1495" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_498314" use="optional" order="65" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfEstimatedFairValueOfTsrPerformanceBasedRestrictedStockUnitAwardsAssumptionsDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1547" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1546" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1547" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1546" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1545" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1546" xlink:to="loc_dei_LegalEntityAxis_1545" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1550" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1545" xlink:to="loc_dei_EntityDomain_1550" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1550_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1545" xlink:to="loc_dei_EntityDomain_1550_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_1543" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1546" xlink:to="loc_us-gaap_AwardTypeAxis_1543" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1548" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_1543" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1548" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1548_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_1543" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1548_default" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_TotalShareholderReturnPerformanceBasedRestrictedStockUnitsMember" xlink:label="loc_ter_TotalShareholderReturnPerformanceBasedRestrictedStockUnitsMember_1554" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1548" xlink:to="loc_ter_TotalShareholderReturnPerformanceBasedRestrictedStockUnitsMember_1554" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FinancialInstrumentAxis" xlink:label="loc_us-gaap_FinancialInstrumentAxis_1544" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1546" xlink:to="loc_us-gaap_FinancialInstrumentAxis_1544" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_1549" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_1544" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_1549" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_1549_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_1544" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_1549_default" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/exch/2020/exch-2020-01-31.xsd#exch_XNYS" xlink:label="loc_exch_XNYS_1555" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_1549" xlink:to="loc_exch_XNYS_1555" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_1552" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1547" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_1552" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_1551" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1547" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_1551" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_1553" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1547" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_1553" use="optional" order="15" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfEstimatedFairValueOfStockOptionsGrantUsingBlackScholesOptionPricingModelDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1561" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_1564" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1561" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_1564" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1560" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1561" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1560" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_1558" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1560" xlink:to="loc_us-gaap_AwardTypeAxis_1558" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1562" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_1558" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1562" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1562_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_1558" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1562_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_1568" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1562" xlink:to="loc_us-gaap_EmployeeStockOptionMember_1568" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1559" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1560" xlink:to="loc_dei_LegalEntityAxis_1559" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1563" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1559" xlink:to="loc_dei_EntityDomain_1563" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1563_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1559" xlink:to="loc_dei_EntityDomain_1563_default" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_1566" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1561" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_1566" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_1565" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1561" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_1565" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_1567" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1561" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_1567" use="optional" order="12" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfStockCompensationPlanActivityDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1574" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_1580" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1574" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_1580" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_1579" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1574" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_1579" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_1577" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1574" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_1577" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber_1587" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1574" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber_1587" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_1583" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1574" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_1583" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber_1588" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1574" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber_1588" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1573" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1574" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1573" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_1571" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1573" xlink:to="loc_us-gaap_AwardTypeAxis_1571" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1575" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_1571" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1575" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1575_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_1571" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1575_default" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_1589" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1575" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_1589" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1572" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1573" xlink:to="loc_dei_LegalEntityAxis_1572" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1576" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1572" xlink:to="loc_dei_EntityDomain_1576" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1576_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1572" xlink:to="loc_dei_EntityDomain_1576_default" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod_1585" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1574" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod_1585" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_814171" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1574" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_814171" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_1578" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1574" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_1578" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_1582" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1574" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_1582" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_1584" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1574" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_1584" use="optional" order="19" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfShareBasedCompensationTotalSharesAvailableDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1594" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_1596" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1594" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_1596" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_1598" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1594" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_1598" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_1599" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1594" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_1599" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1593" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1594" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1593" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1592" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1593" xlink:to="loc_dei_LegalEntityAxis_1592" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1595" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1592" xlink:to="loc_dei_EntityDomain_1595" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1595_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1592" xlink:to="loc_dei_EntityDomain_1595_default" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_1597" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1594" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_1597" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_814177" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1594" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_814177" use="optional" order="9" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfWeightedAverageRestrictedStockUnitAwardFairValueDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1605" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1604" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1605" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1604" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1603" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1604" xlink:to="loc_dei_LegalEntityAxis_1603" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1606" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1603" xlink:to="loc_dei_EntityDomain_1606" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1606_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1603" xlink:to="loc_dei_EntityDomain_1606_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_1608" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1605" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_1608" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_1610" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1605" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_1610" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_1609" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1605" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_1609" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_1607" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1605" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_1607" use="optional" order="8" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfRestrictedStockUnitAwardsAggregateIntrinsicValueDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1617" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1616" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1617" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1616" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_1614" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1616" xlink:to="loc_us-gaap_AwardTypeAxis_1614" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1618" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_1614" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1618" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1618_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_1614" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1618_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_1623" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1618" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_1623" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1615" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1616" xlink:to="loc_dei_LegalEntityAxis_1615" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1619" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1615" xlink:to="loc_dei_EntityDomain_1619" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1619_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1615" xlink:to="loc_dei_EntityDomain_1619_default" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueOutstanding" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueOutstanding_1621" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1617" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueOutstanding_1621" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueVested" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueVested_1620" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1617" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueVested_1620" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedAndExpectedToVestIntrinsicValue" xlink:label="loc_ter_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedAndExpectedToVestIntrinsicValue_1622" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1617" xlink:to="loc_ter_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedAndExpectedToVestIntrinsicValue_1622" use="optional" order="11" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfRestrictedStockUnitsWeightedAverageRemainingContractualTermsDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1629" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms_1632" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1629" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms_1632" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1628" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1629" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1628" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_1626" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1628" xlink:to="loc_us-gaap_AwardTypeAxis_1626" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1630" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_1626" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1630" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1630_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_1626" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1630_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_1634" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1630" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_1634" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1627" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1628" xlink:to="loc_dei_LegalEntityAxis_1627" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1631" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1627" xlink:to="loc_dei_EntityDomain_1631" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1631_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1627" xlink:to="loc_dei_EntityDomain_1631_default" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionVestedAndExpectedToVestWeightedAverageRemainingContractualTerm" xlink:label="loc_ter_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionVestedAndExpectedToVestWeightedAverageRemainingContractualTerm_1633" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1629" xlink:to="loc_ter_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionVestedAndExpectedToVestWeightedAverageRemainingContractualTerm_1633" use="optional" order="10" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfWeightedAverageStockOptionsExercisePriceDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1639" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_1645" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1639" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_1645" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_1641" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1639" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_1641" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_1643" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1639" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_1643" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1638" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1639" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1638" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1637" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1638" xlink:to="loc_dei_LegalEntityAxis_1637" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1640" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1637" xlink:to="loc_dei_EntityDomain_1640" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1640_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1637" xlink:to="loc_dei_EntityDomain_1640_default" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_1642" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1639" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_1642" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice_814187" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1639" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice_814187" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice_814188" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1639" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice_814188" use="optional" order="10" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfStockOptionAggregatedIntrinsicValueInformationDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1650" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue_1654" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1650" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue_1654" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_1652" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1650" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_1652" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_1653" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1650" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_1653" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_1655" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1650" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_1655" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1649" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1650" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1649" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1648" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1649" xlink:to="loc_dei_LegalEntityAxis_1648" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1651" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1648" xlink:to="loc_dei_EntityDomain_1651" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1651_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1648" xlink:to="loc_dei_EntityDomain_1651_default" use="optional" order="8" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfStockOptionsWeightedAverageRemainingContractualTermsDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1660" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1659" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1660" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1659" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1658" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1659" xlink:to="loc_dei_LegalEntityAxis_1658" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1661" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1658" xlink:to="loc_dei_EntityDomain_1661" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1661_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1658" xlink:to="loc_dei_EntityDomain_1661_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_1664" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1660" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_1664" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_1662" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1660" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_1662" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1_1663" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1660" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1_1663" use="optional" order="7" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/StockBasedCompensationDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_1686" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_1691" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_1686" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_1691" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax_1693" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_1686" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax_1693" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_1692" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_1686" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_1692" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_1690" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_1686" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_1690" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1689" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_1690" xlink:to="loc_dei_LegalEntityAxis_1689" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1697" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1689" xlink:to="loc_dei_EntityDomain_1697" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1697_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1689" xlink:to="loc_dei_EntityDomain_1697_default" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_1687" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_1690" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_1687" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_1688" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_1687" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_1688" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_1688_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_1687" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_1688_default" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_CostOfRevenuesMember" xlink:label="loc_ter_CostOfRevenuesMember_1694" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_1688" xlink:to="loc_ter_CostOfRevenuesMember_1694" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SellingAndAdministrativeMember" xlink:label="loc_ter_SellingAndAdministrativeMember_1696" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_1688" xlink:to="loc_ter_SellingAndAdministrativeMember_1696" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_EngineeringAndDevelopmentMember" xlink:label="loc_ter_EngineeringAndDevelopmentMember_1695" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_1688" xlink:to="loc_ter_EngineeringAndDevelopmentMember_1695" use="optional" order="13" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/SavingsPlanAdditionalInformationDetail">
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SavingsPlanLineItems" xlink:label="loc_ter_SavingsPlanLineItems_1703" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedContributionPlanEmployersMatchingContributionAnnualVestingPercentage" xlink:label="loc_us-gaap_DefinedContributionPlanEmployersMatchingContributionAnnualVestingPercentage_1711" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_SavingsPlanLineItems_1703" xlink:to="loc_us-gaap_DefinedContributionPlanEmployersMatchingContributionAnnualVestingPercentage_1711" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedContributionPlanCostRecognized" xlink:label="loc_us-gaap_DefinedContributionPlanCostRecognized_1713" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_SavingsPlanLineItems_1703" xlink:to="loc_us-gaap_DefinedContributionPlanCostRecognized_1713" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch" xlink:label="loc_us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch_1709" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_SavingsPlanLineItems_1703" xlink:to="loc_us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch_1709" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_MaximumEmploymentPeriodConsideredForVestingOfEmployersContribution" xlink:label="loc_ter_MaximumEmploymentPeriodConsideredForVestingOfEmployersContribution_1712" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_SavingsPlanLineItems_1703" xlink:to="loc_ter_MaximumEmploymentPeriodConsideredForVestingOfEmployersContribution_1712" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SavingsPlanMaximumPercentageOfEmployeesContributionAllowable" xlink:label="loc_ter_SavingsPlanMaximumPercentageOfEmployeesContributionAllowable_1708" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_SavingsPlanLineItems_1703" xlink:to="loc_ter_SavingsPlanMaximumPercentageOfEmployeesContributionAllowable_1708" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" xlink:label="loc_us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent_1710" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_SavingsPlanLineItems_1703" xlink:to="loc_us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent_1710" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ScheduleOfSavingsPlanTable" xlink:label="loc_ter_ScheduleOfSavingsPlanTable_1704" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ter_SavingsPlanLineItems_1703" xlink:to="loc_ter_ScheduleOfSavingsPlanTable_1704" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1700" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_ScheduleOfSavingsPlanTable_1704" xlink:to="loc_dei_LegalEntityAxis_1700" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1705" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1700" xlink:to="loc_dei_EntityDomain_1705" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1705_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1700" xlink:to="loc_dei_EntityDomain_1705_default" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_1701" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_ScheduleOfSavingsPlanTable_1704" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_1701" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_1702" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_1701" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_1702" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_1702_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_1701" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_1702_default" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SavingsPlanMember" xlink:label="loc_ter_SavingsPlanMember_1707" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_1702" xlink:to="loc_ter_SavingsPlanMember_1707" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_UsQualifiedPensionPlanMember" xlink:label="loc_ter_UsQualifiedPensionPlanMember_1706" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_1702" xlink:to="loc_ter_UsQualifiedPensionPlanMember_1706" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionAndOtherPostretirementAndPostemploymentBenefitPlansLiabilitiesCurrentAndNoncurrent" xlink:label="loc_us-gaap_PensionAndOtherPostretirementAndPostemploymentBenefitPlansLiabilitiesCurrentAndNoncurrent_331909" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_SavingsPlanLineItems_1703" xlink:to="loc_us-gaap_PensionAndOtherPostretirementAndPostemploymentBenefitPlansLiabilitiesCurrentAndNoncurrent_331909" use="optional" order="16" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfIncomeLossBeforeIncomeTaxesDetail">
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_IncomeTaxDisclosureLineItems" xlink:label="loc_ter_IncomeTaxDisclosureLineItems_1716" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign_1720" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1716" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign_1720" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_IncomeTaxDisclosureTable" xlink:label="loc_ter_IncomeTaxDisclosureTable_1717" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1716" xlink:to="loc_ter_IncomeTaxDisclosureTable_1717" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1718" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_IncomeTaxDisclosureTable_1717" xlink:to="loc_dei_LegalEntityAxis_1718" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1722" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1718" xlink:to="loc_dei_EntityDomain_1722" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1722_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1718" xlink:to="loc_dei_EntityDomain_1722_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic_1719" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1716" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic_1719" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_1721" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1716" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_1721" use="optional" order="7" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfProvisionBenefitForIncomeTaxesFromOperationsDetail">
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_IncomeTaxDisclosureLineItems" xlink:label="loc_ter_IncomeTaxDisclosureLineItems_1725" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_IncomeTaxDisclosureTable" xlink:label="loc_ter_IncomeTaxDisclosureTable_1726" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1725" xlink:to="loc_ter_IncomeTaxDisclosureTable_1726" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1727" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_IncomeTaxDisclosureTable_1726" xlink:to="loc_dei_LegalEntityAxis_1727" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1737" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1727" xlink:to="loc_dei_EntityDomain_1737" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1737_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1727" xlink:to="loc_dei_EntityDomain_1737_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_CurrentIncomeTaxExpenseBenefit_1731" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1725" xlink:to="loc_us-gaap_CurrentIncomeTaxExpenseBenefit_1731" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:label="loc_us-gaap_CurrentStateAndLocalTaxExpenseBenefit_1730" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1725" xlink:to="loc_us-gaap_CurrentStateAndLocalTaxExpenseBenefit_1730" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_DeferredFederalIncomeTaxExpenseBenefit_1732" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1725" xlink:to="loc_us-gaap_DeferredFederalIncomeTaxExpenseBenefit_1732" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DeferredIncomeTaxExpenseBenefitNetOfAdjustments" xlink:label="loc_ter_DeferredIncomeTaxExpenseBenefitNetOfAdjustments_1735" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1725" xlink:to="loc_ter_DeferredIncomeTaxExpenseBenefitNetOfAdjustments_1735" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_1734" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1725" xlink:to="loc_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_1734" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CurrentFederalTaxExpenseBenefit" xlink:label="loc_us-gaap_CurrentFederalTaxExpenseBenefit_1728" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1725" xlink:to="loc_us-gaap_CurrentFederalTaxExpenseBenefit_1728" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredForeignIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_DeferredForeignIncomeTaxExpenseBenefit_1733" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1725" xlink:to="loc_us-gaap_DeferredForeignIncomeTaxExpenseBenefit_1733" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CurrentForeignTaxExpenseBenefit" xlink:label="loc_us-gaap_CurrentForeignTaxExpenseBenefit_1729" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1725" xlink:to="loc_us-gaap_CurrentForeignTaxExpenseBenefit_1729" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_829005" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1725" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_829005" use="optional" order="13" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/IncomeTaxesAdditionalInformationDetail">
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_IncomeTaxesLineItems" xlink:label="loc_ter_IncomeTaxesLineItems_1742" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxExaminationPenaltiesAndInterestExpense" xlink:label="loc_us-gaap_IncomeTaxExaminationPenaltiesAndInterestExpense_1769" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxesLineItems_1742" xlink:to="loc_us-gaap_IncomeTaxExaminationPenaltiesAndInterestExpense_1769" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_TaxCutsAndJobsActOf2017CorrelativeAdjustmentsOnUncertainTaxPositions" xlink:label="loc_ter_TaxCutsAndJobsActOf2017CorrelativeAdjustmentsOnUncertainTaxPositions_1755" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxesLineItems_1742" xlink:to="loc_ter_TaxCutsAndJobsActOf2017CorrelativeAdjustmentsOnUncertainTaxPositions_1755" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsGeneralBusiness" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsGeneralBusiness_1761" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxesLineItems_1742" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsGeneralBusiness_1761" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsValuationAllowance" xlink:label="loc_us-gaap_DeferredTaxAssetsValuationAllowance_1759" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxesLineItems_1742" xlink:to="loc_us-gaap_DeferredTaxAssetsValuationAllowance_1759" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsTaxCreditCarryforwards" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwards_1763" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxesLineItems_1742" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwards_1763" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_IncomeTaxesTable" xlink:label="loc_ter_IncomeTaxesTable_1743" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ter_IncomeTaxesLineItems_1742" xlink:to="loc_ter_IncomeTaxesTable_1743" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxAuthorityAxis" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_1740" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_IncomeTaxesTable_1743" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_1740" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_1741" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_1740" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_1741" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_1741_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_1740" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_1741_default" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DomesticCountryMember" xlink:label="loc_us-gaap_DomesticCountryMember_1747" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_1741" xlink:to="loc_us-gaap_DomesticCountryMember_1747" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StateAndLocalJurisdictionMember" xlink:label="loc_us-gaap_StateAndLocalJurisdictionMember_1748" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_1741" xlink:to="loc_us-gaap_StateAndLocalJurisdictionMember_1748" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_321745" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_IncomeTaxesTable_1743" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_321745" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_321746" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_321745" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_321746" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_321746_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_321745" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_321746_default" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxPeriodAxis" xlink:label="loc_us-gaap_TaxPeriodAxis_1745" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_IncomeTaxesTable_1743" xlink:to="loc_us-gaap_TaxPeriodAxis_1745" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxPeriodDomain" xlink:label="loc_us-gaap_TaxPeriodDomain_1746" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TaxPeriodAxis_1745" xlink:to="loc_us-gaap_TaxPeriodDomain_1746" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxPeriodDomain" xlink:label="loc_us-gaap_TaxPeriodDomain_1746_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TaxPeriodAxis_1745" xlink:to="loc_us-gaap_TaxPeriodDomain_1746_default" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DoNotExpireMember" xlink:label="loc_ter_DoNotExpireMember_1773" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxPeriodDomain_1746" xlink:to="loc_ter_DoNotExpireMember_1773" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EarliestTaxYearMember" xlink:label="loc_us-gaap_EarliestTaxYearMember_1771" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxPeriodDomain_1746" xlink:to="loc_us-gaap_EarliestTaxYearMember_1771" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LatestTaxYearMember" xlink:label="loc_us-gaap_LatestTaxYearMember_1772" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxPeriodDomain_1746" xlink:to="loc_us-gaap_LatestTaxYearMember_1772" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1744" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_IncomeTaxesTable_1743" xlink:to="loc_dei_LegalEntityAxis_1744" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1770" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1744" xlink:to="loc_dei_EntityDomain_1770" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1770_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1744" xlink:to="loc_dei_EntityDomain_1770_default" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxCreditCarryforwardAxis" xlink:label="loc_us-gaap_TaxCreditCarryforwardAxis_415378" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_IncomeTaxesTable_1743" xlink:to="loc_us-gaap_TaxCreditCarryforwardAxis_415378" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxCreditCarryforwardNameDomain" xlink:label="loc_us-gaap_TaxCreditCarryforwardNameDomain_415380" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TaxCreditCarryforwardAxis_415378" xlink:to="loc_us-gaap_TaxCreditCarryforwardNameDomain_415380" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxCreditCarryforwardNameDomain" xlink:label="loc_us-gaap_TaxCreditCarryforwardNameDomain_415380_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TaxCreditCarryforwardAxis_415378" xlink:to="loc_us-gaap_TaxCreditCarryforwardNameDomain_415380_default" use="optional" order="26" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_474597" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_IncomeTaxesTable_1743" xlink:to="loc_srt_RangeAxis_474597" use="optional" order="27" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_474598" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_474597" xlink:to="loc_srt_RangeMember_474598" use="optional" order="28" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_474598_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_474597" xlink:to="loc_srt_RangeMember_474598_default" use="optional" order="29" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="loc_us-gaap_TypeOfArrangementAxis_814079" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_IncomeTaxesTable_1743" xlink:to="loc_us-gaap_TypeOfArrangementAxis_814079" use="optional" order="30" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_814081" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TypeOfArrangementAxis_814079" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_814081" use="optional" order="31" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_814081_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TypeOfArrangementAxis_814079" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_814081_default" use="optional" order="32" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_IntercompanyCostSharingArrangementMember" xlink:label="loc_ter_IntercompanyCostSharingArrangementMember_814083" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_814081" xlink:to="loc_ter_IntercompanyCostSharingArrangementMember_814083" use="optional" order="33" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_PossibleEventAxis" xlink:label="loc_ter_PossibleEventAxis_828937" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_IncomeTaxesTable_1743" xlink:to="loc_ter_PossibleEventAxis_828937" use="optional" order="34" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_PossibleEventDomain" xlink:label="loc_ter_PossibleEventDomain_828938" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_ter_PossibleEventAxis_828937" xlink:to="loc_ter_PossibleEventDomain_828938" use="optional" order="35" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_PossibleEventDomain" xlink:label="loc_ter_PossibleEventDomain_828938_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_ter_PossibleEventAxis_828937" xlink:to="loc_ter_PossibleEventDomain_828938_default" use="optional" order="36" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_PossibleLapseOfStatutesOfLimitationsMember" xlink:label="loc_ter_PossibleLapseOfStatutesOfLimitationsMember_828939" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_PossibleEventDomain_828938" xlink:to="loc_ter_PossibleLapseOfStatutesOfLimitationsMember_828939" use="optional" order="37" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_1749" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxesLineItems_1742" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_1749" use="optional" order="38" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxHolidayIncomeTaxBenefitsPerShare" xlink:label="loc_us-gaap_IncomeTaxHolidayIncomeTaxBenefitsPerShare_1757" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxesLineItems_1742" xlink:to="loc_us-gaap_IncomeTaxHolidayIncomeTaxBenefitsPerShare_1757" use="optional" order="39" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxHolidayTerminationDate" xlink:label="loc_us-gaap_IncomeTaxHolidayTerminationDate_1758" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxesLineItems_1742" xlink:to="loc_us-gaap_IncomeTaxHolidayTerminationDate_1758" use="optional" order="40" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxReconciliationTaxHolidays" xlink:label="loc_us-gaap_IncomeTaxReconciliationTaxHolidays_1756" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxesLineItems_1742" xlink:to="loc_us-gaap_IncomeTaxReconciliationTaxHolidays_1756" use="optional" order="41" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_1750" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxesLineItems_1742" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_1750" use="optional" order="42" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_TaxCreditCarryforwardExpirationYear" xlink:label="loc_ter_TaxCreditCarryforwardExpirationYear_1762" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxesLineItems_1742" xlink:to="loc_ter_TaxCreditCarryforwardExpirationYear_1762" use="optional" order="43" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsIncomeTaxExpenseBenefit" xlink:label="loc_ter_TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsIncomeTaxExpenseBenefit_1753" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxesLineItems_1742" xlink:to="loc_ter_TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsIncomeTaxExpenseBenefit_1753" use="optional" order="44" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_UnrecognizedTaxBenefitsIfRecognizedWouldImpactDeferredTaxes" xlink:label="loc_ter_UnrecognizedTaxBenefitsIfRecognizedWouldImpactDeferredTaxes_1766" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxesLineItems_1742" xlink:to="loc_ter_UnrecognizedTaxBenefitsIfRecognizedWouldImpactDeferredTaxes_1766" use="optional" order="45" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_1768" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxesLineItems_1742" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_1768" use="optional" order="46" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxCreditCarryforwardAmount" xlink:label="loc_us-gaap_TaxCreditCarryforwardAmount_1760" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxesLineItems_1742" xlink:to="loc_us-gaap_TaxCreditCarryforwardAmount_1760" use="optional" order="47" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_1765" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxesLineItems_1742" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_1765" use="optional" order="48" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxCutsAndJobsActOf2017IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_TaxCutsAndJobsActOf2017IncomeTaxExpenseBenefit_819272" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxesLineItems_1742" xlink:to="loc_us-gaap_TaxCutsAndJobsActOf2017IncomeTaxExpenseBenefit_819272" use="optional" order="49" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_UnrecognizedTaxBenefits" xlink:label="loc_us-gaap_UnrecognizedTaxBenefits_1764" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxesLineItems_1742" xlink:to="loc_us-gaap_UnrecognizedTaxBenefits_1764" use="optional" order="50" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxCutsAndJobsActOf2017ChangeInTaxRateIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_TaxCutsAndJobsActOf2017ChangeInTaxRateIncomeTaxExpenseBenefit_819293" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxesLineItems_1742" xlink:to="loc_us-gaap_TaxCutsAndJobsActOf2017ChangeInTaxRateIncomeTaxExpenseBenefit_819293" use="optional" order="51" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible" xlink:label="loc_us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible_828935" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxesLineItems_1742" xlink:to="loc_us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible_828935" use="optional" order="52" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfReconciliationOfEffectiveTaxRateDetail">
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_IncomeTaxDisclosureLineItems" xlink:label="loc_ter_IncomeTaxDisclosureLineItems_1776" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_1794" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1776" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_1794" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_EffectiveIncomeTaxRateReconcilationForeignDerivedIntangibleIncome" xlink:label="loc_ter_EffectiveIncomeTaxRateReconcilationForeignDerivedIntangibleIncome_1781" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1776" xlink:to="loc_ter_EffectiveIncomeTaxRateReconcilationForeignDerivedIntangibleIncome_1781" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_1779" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1776" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_1779" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate_1782" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1776" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate_1782" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments_1793" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1776" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments_1793" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_IncomeTaxDisclosureTable" xlink:label="loc_ter_IncomeTaxDisclosureTable_1777" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1776" xlink:to="loc_ter_IncomeTaxDisclosureTable_1777" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1778" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_IncomeTaxDisclosureTable_1777" xlink:to="loc_dei_LegalEntityAxis_1778" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1795" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1778" xlink:to="loc_dei_EntityDomain_1795" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1795_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1778" xlink:to="loc_dei_EntityDomain_1795_default" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential_1784" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1776" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential_1784" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_1788" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1776" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_1788" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsForeign" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsForeign_1785" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1776" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsForeign_1785" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTaxContingencies" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxContingencies_1783" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1776" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxContingencies_1783" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost_1787" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1776" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost_1787" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsResearch" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsResearch_1786" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1776" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsResearch_1786" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017TransitionTax" xlink:label="loc_ter_EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017TransitionTax_1780" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1776" xlink:to="loc_ter_EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017TransitionTax_1780" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_EffectiveIncomeTaxRateGlobalIntangibleLowTaxedIncome" xlink:label="loc_ter_EffectiveIncomeTaxRateGlobalIntangibleLowTaxedIncome_813535" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1776" xlink:to="loc_ter_EffectiveIncomeTaxRateGlobalIntangibleLowTaxedIncome_813535" use="optional" order="17" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfComponentsOfDeferredTaxAssetsLiabilitiesDetail">
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_IncomeTaxDisclosureLineItems" xlink:label="loc_ter_IncomeTaxDisclosureLineItems_1798" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsGross" xlink:label="loc_us-gaap_DeferredTaxAssetsGross_1811" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_us-gaap_DeferredTaxAssetsGross_1811" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsLiabilitiesNet" xlink:label="loc_us-gaap_DeferredTaxAssetsLiabilitiesNet_1818" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_us-gaap_DeferredTaxAssetsLiabilitiesNet_1818" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsInventory" xlink:label="loc_us-gaap_DeferredTaxAssetsInventory_1803" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_us-gaap_DeferredTaxAssetsInventory_1803" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsNet" xlink:label="loc_us-gaap_DeferredTaxAssetsNet_1813" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_us-gaap_DeferredTaxAssetsNet_1813" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsValuationAllowance" xlink:label="loc_us-gaap_DeferredTaxAssetsValuationAllowance_1812" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_us-gaap_DeferredTaxAssetsValuationAllowance_1812" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredIncomeTaxLiabilities" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilities_1817" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_us-gaap_DeferredIncomeTaxLiabilities_1817" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxLiabilitiesInvestments" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesInvestments_1816" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_us-gaap_DeferredTaxLiabilitiesInvestments_1816" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsDeferredIncome" xlink:label="loc_us-gaap_DeferredTaxAssetsDeferredIncome_1805" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_us-gaap_DeferredTaxAssetsDeferredIncome_1805" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" xlink:label="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_1807" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_1807" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsOther" xlink:label="loc_us-gaap_DeferredTaxAssetsOther_1810" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_us-gaap_DeferredTaxAssetsOther_1810" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsTaxCreditCarryforwards" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwards_1801" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwards_1801" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsCompensatedAbsences" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsCompensatedAbsences_1808" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsCompensatedAbsences_1808" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensions" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensions_1802" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensions_1802" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost_1806" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost_1806" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals_1804" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals_1804" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets_1814" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets_1814" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_IncomeTaxDisclosureTable" xlink:label="loc_ter_IncomeTaxDisclosureTable_1799" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_ter_IncomeTaxDisclosureTable_1799" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1800" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_IncomeTaxDisclosureTable_1799" xlink:to="loc_dei_LegalEntityAxis_1800" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1819" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1800" xlink:to="loc_dei_EntityDomain_1819" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1819_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1800" xlink:to="loc_dei_EntityDomain_1819_default" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsImpairmentLosses" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsImpairmentLosses_813545" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsImpairmentLosses_813545" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment_1815" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment_1815" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DeferredTaxAssetsTaxDeferredExpenseLeaseLiability" xlink:label="loc_ter_DeferredTaxAssetsTaxDeferredExpenseLeaseLiability_826822" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_ter_DeferredTaxAssetsTaxDeferredExpenseLeaseLiability_826822" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DeferredTaxLiabilitiesContingentConsideration" xlink:label="loc_ter_DeferredTaxLiabilitiesContingentConsideration_826829" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_ter_DeferredTaxLiabilitiesContingentConsideration_826829" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxLiabilitiesOther" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesOther_826831" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_us-gaap_DeferredTaxLiabilitiesOther_826831" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_DeferredTaxLiabilitiesRightOfUseAssets" xlink:label="loc_ter_DeferredTaxLiabilitiesRightOfUseAssets_826827" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1798" xlink:to="loc_ter_DeferredTaxLiabilitiesRightOfUseAssets_826827" use="optional" order="26" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/SummaryOfOperatingLossCarryforwardsDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLossCarryforwardsLineItems" xlink:label="loc_us-gaap_OperatingLossCarryforwardsLineItems_1823" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsDomestic" xlink:label="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsDomestic_1828" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_1823" xlink:to="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsDomestic_1828" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsForeign" xlink:label="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsForeign_1830" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_1823" xlink:to="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsForeign_1830" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLossCarryforwardsTable" xlink:label="loc_us-gaap_OperatingLossCarryforwardsTable_1824" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_1823" xlink:to="loc_us-gaap_OperatingLossCarryforwardsTable_1824" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1822" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OperatingLossCarryforwardsTable_1824" xlink:to="loc_dei_LegalEntityAxis_1822" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1827" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1822" xlink:to="loc_dei_EntityDomain_1827" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1827_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1822" xlink:to="loc_dei_EntityDomain_1827_default" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxPeriodAxis" xlink:label="loc_us-gaap_TaxPeriodAxis_1825" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OperatingLossCarryforwardsTable_1824" xlink:to="loc_us-gaap_TaxPeriodAxis_1825" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxPeriodDomain" xlink:label="loc_us-gaap_TaxPeriodDomain_1826" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TaxPeriodAxis_1825" xlink:to="loc_us-gaap_TaxPeriodDomain_1826" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxPeriodDomain" xlink:label="loc_us-gaap_TaxPeriodDomain_1826_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TaxPeriodAxis_1825" xlink:to="loc_us-gaap_TaxPeriodDomain_1826_default" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_OperatingLossCarryforwardsExpiringTwoThousandAndTwentyTwoMember" xlink:label="loc_ter_OperatingLossCarryforwardsExpiringTwoThousandAndTwentyTwoMember_1834" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxPeriodDomain_1826" xlink:to="loc_ter_OperatingLossCarryforwardsExpiringTwoThousandAndTwentyTwoMember_1834" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_OperatingLossCarryforwardsExpiringTwoThousandTwentySixToTwoThousandThirtyMember" xlink:label="loc_ter_OperatingLossCarryforwardsExpiringTwoThousandTwentySixToTwoThousandThirtyMember_814017" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxPeriodDomain_1826" xlink:to="loc_ter_OperatingLossCarryforwardsExpiringTwoThousandTwentySixToTwoThousandThirtyMember_814017" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_OperatingLossCarryforwardsExpiringTwoThousandThirtyOneToTwoThousandThirtyFiveMember" xlink:label="loc_ter_OperatingLossCarryforwardsExpiringTwoThousandThirtyOneToTwoThousandThirtyFiveMember_814018" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxPeriodDomain_1826" xlink:to="loc_ter_OperatingLossCarryforwardsExpiringTwoThousandThirtyOneToTwoThousandThirtyFiveMember_814018" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_OperatingLossCarryforwardsExpiringBeyondTwoThousandThirtyFiveMember" xlink:label="loc_ter_OperatingLossCarryforwardsExpiringBeyondTwoThousandThirtyFiveMember_814025" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxPeriodDomain_1826" xlink:to="loc_ter_OperatingLossCarryforwardsExpiringBeyondTwoThousandThirtyFiveMember_814025" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_OperatingLossCarryforwardsNonExpiringMember" xlink:label="loc_ter_OperatingLossCarryforwardsNonExpiringMember_814038" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxPeriodDomain_1826" xlink:to="loc_ter_OperatingLossCarryforwardsNonExpiringMember_814038" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_OperatingLossCarryForwardsExpiringTwoThousandTwentyOneMember" xlink:label="loc_ter_OperatingLossCarryForwardsExpiringTwoThousandTwentyOneMember_1833" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxPeriodDomain_1826" xlink:to="loc_ter_OperatingLossCarryForwardsExpiringTwoThousandTwentyOneMember_1833" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_OperatingLossCarryforwardsExpiringTwoThousandAndTwentyThreeMember" xlink:label="loc_ter_OperatingLossCarryforwardsExpiringTwoThousandAndTwentyThreeMember_1835" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxPeriodDomain_1826" xlink:to="loc_ter_OperatingLossCarryforwardsExpiringTwoThousandAndTwentyThreeMember_1835" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_OperatingLossCarryforwardsExpiringTwoThousandTwentyFourMember" xlink:label="loc_ter_OperatingLossCarryforwardsExpiringTwoThousandTwentyFourMember_814044" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxPeriodDomain_1826" xlink:to="loc_ter_OperatingLossCarryforwardsExpiringTwoThousandTwentyFourMember_814044" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_OperatingLossCarryforwardsExpiringTwoThousandTwentyFiveMember" xlink:label="loc_ter_OperatingLossCarryforwardsExpiringTwoThousandTwentyFiveMember_814045" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxPeriodDomain_1826" xlink:to="loc_ter_OperatingLossCarryforwardsExpiringTwoThousandTwentyFiveMember_814045" use="optional" order="18" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfUnrecognizedTaxBenefitsDetail">
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_IncomeTaxDisclosureLineItems" xlink:label="loc_ter_IncomeTaxDisclosureLineItems_1842" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions_1848" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1842" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions_1848" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions_1847" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1842" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions_1847" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations_1849" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1842" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations_1849" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_IncomeTaxDisclosureTable" xlink:label="loc_ter_IncomeTaxDisclosureTable_1843" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1842" xlink:to="loc_ter_IncomeTaxDisclosureTable_1843" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1844" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_IncomeTaxDisclosureTable_1843" xlink:to="loc_dei_LegalEntityAxis_1844" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1852" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1844" xlink:to="loc_dei_EntityDomain_1852" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1852_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1844" xlink:to="loc_dei_EntityDomain_1852_default" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions_1846" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1842" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions_1846" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_UnrecognizedTaxBenefits" xlink:label="loc_us-gaap_UnrecognizedTaxBenefits_1845" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_IncomeTaxDisclosureLineItems_1842" xlink:to="loc_us-gaap_UnrecognizedTaxBenefits_1845" use="optional" order="9" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/OperatingSegmentGeographicAndSignificantCustomerInformationAdditionalInformationDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_1864" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskPercentage1" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_1874" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1864" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_1874" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_NumberOfCustomerAccountedForTenPercentOrGreaterRevenue" xlink:label="loc_ter_NumberOfCustomerAccountedForTenPercentOrGreaterRevenue_1875" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1864" xlink:to="loc_ter_NumberOfCustomerAccountedForTenPercentOrGreaterRevenue_1875" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NumberOfOperatingSegments" xlink:label="loc_us-gaap_NumberOfOperatingSegments_1873" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1864" xlink:to="loc_us-gaap_NumberOfOperatingSegments_1873" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1862" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1864" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1862" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_1856" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1862" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_1856" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_1855" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_1856" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_1855" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_1855_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_1856" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_1855_default" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SalesRevenueNetMember" xlink:label="loc_us-gaap_SalesRevenueNetMember_1866" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_1855" xlink:to="loc_us-gaap_SalesRevenueNetMember_1866" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_1865" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1862" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_1865" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_1863" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_1865" xlink:to="loc_us-gaap_SegmentDomain_1863" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_1863_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_1865" xlink:to="loc_us-gaap_SegmentDomain_1863_default" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SemiconductorTestMember" xlink:label="loc_ter_SemiconductorTestMember_1872" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_1863" xlink:to="loc_ter_SemiconductorTestMember_1872" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1859" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1862" xlink:to="loc_dei_LegalEntityAxis_1859" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1869" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1859" xlink:to="loc_dei_EntityDomain_1869" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1869_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1859" xlink:to="loc_dei_EntityDomain_1869_default" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MajorCustomersAxis" xlink:label="loc_srt_MajorCustomersAxis_1860" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1862" xlink:to="loc_srt_MajorCustomersAxis_1860" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_NameOfMajorCustomerDomain" xlink:label="loc_srt_NameOfMajorCustomerDomain_1861" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_1860" xlink:to="loc_srt_NameOfMajorCustomerDomain_1861" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_NameOfMajorCustomerDomain" xlink:label="loc_srt_NameOfMajorCustomerDomain_1861_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_1860" xlink:to="loc_srt_NameOfMajorCustomerDomain_1861_default" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_CustomerOneMember" xlink:label="loc_ter_CustomerOneMember_1870" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_1861" xlink:to="loc_ter_CustomerOneMember_1870" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskByTypeAxis" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_1857" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1862" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_1857" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_1858" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_1857" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_1858" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_1858_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_1857" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_1858_default" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueFromRightsConcentrationRiskMember" xlink:label="loc_us-gaap_RevenueFromRightsConcentrationRiskMember_1867" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_1858" xlink:to="loc_us-gaap_RevenueFromRightsConcentrationRiskMember_1867" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CustomerConcentrationRiskMember" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember_1868" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_1858" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember_1868" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SeriesOfCustomerAxis" xlink:label="loc_ter_SeriesOfCustomerAxis_827188" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1862" xlink:to="loc_ter_SeriesOfCustomerAxis_827188" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SeriesOfCustomerDomain" xlink:label="loc_ter_SeriesOfCustomerDomain_827190" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_ter_SeriesOfCustomerAxis_827188" xlink:to="loc_ter_SeriesOfCustomerDomain_827190" use="optional" order="26" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SeriesOfCustomerDomain" xlink:label="loc_ter_SeriesOfCustomerDomain_827190_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_ter_SeriesOfCustomerAxis_827188" xlink:to="loc_ter_SeriesOfCustomerDomain_827190_default" use="optional" order="27" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SeriesOfCustomerMember" xlink:label="loc_ter_SeriesOfCustomerMember_827196" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_SeriesOfCustomerDomain_827190" xlink:to="loc_ter_SeriesOfCustomerMember_827196" use="optional" order="28" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfSegmentInformationDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_1881" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Assets" xlink:label="loc_us-gaap_Assets_1891" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1881" xlink:to="loc_us-gaap_Assets_1891" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_1892" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1881" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_1892" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_1893" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1881" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_1893" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_1890" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1881" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_1890" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Revenues" xlink:label="loc_us-gaap_Revenues_1889" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1881" xlink:to="loc_us-gaap_Revenues_1889" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1879" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1881" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1879" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1878" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1879" xlink:to="loc_dei_LegalEntityAxis_1878" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1883" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1878" xlink:to="loc_dei_EntityDomain_1883" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1883_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1878" xlink:to="loc_dei_EntityDomain_1883_default" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_1882" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1879" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_1882" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_1880" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_1882" xlink:to="loc_us-gaap_SegmentDomain_1880" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_1880_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_1882" xlink:to="loc_us-gaap_SegmentDomain_1880_default" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_CorporateAndOthersMember" xlink:label="loc_ter_CorporateAndOthersMember_398321" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_1880" xlink:to="loc_ter_CorporateAndOthersMember_398321" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_IndustrialAutomationMember" xlink:label="loc_ter_IndustrialAutomationMember_1886" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_1880" xlink:to="loc_ter_IndustrialAutomationMember_1886" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SystemsTestGroupMember" xlink:label="loc_ter_SystemsTestGroupMember_1885" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_1880" xlink:to="loc_ter_SystemsTestGroupMember_1885" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_WirelessTestMember" xlink:label="loc_ter_WirelessTestMember_1887" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_1880" xlink:to="loc_ter_WirelessTestMember_1887" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SemiconductorTestMember" xlink:label="loc_ter_SemiconductorTestMember_1884" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_1880" xlink:to="loc_ter_SemiconductorTestMember_1884" use="optional" order="17" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfSegmentReportingInformationBySegmentChargesDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_1906" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_CostOfRevenuesProvisionForExcessAndObsoleteInventory" xlink:label="loc_ter_CostOfRevenuesProvisionForExcessAndObsoleteInventory_1922" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1906" xlink:to="loc_ter_CostOfRevenuesProvisionForExcessAndObsoleteInventory_1922" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_1921" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1906" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_1921" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_1930" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1906" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_1930" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1904" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1906" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1904" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_1896" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1904" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_1896" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_1897" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_1896" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_1897" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_1897_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_1896" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_1897_default" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_1899" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1904" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_1899" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1898" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_1899" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1898" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1898_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_1899" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1898_default" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_UniversalRobotsMember" xlink:label="loc_ter_UniversalRobotsMember_1910" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1898" xlink:to="loc_ter_UniversalRobotsMember_1910" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_MobileIndustrialRobotsApsMember" xlink:label="loc_ter_MobileIndustrialRobotsApsMember_1913" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1898" xlink:to="loc_ter_MobileIndustrialRobotsApsMember_1913" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_1900" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1904" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_1900" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_1901" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_1900" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_1901" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_1901_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_1900" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_1901_default" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherOperatingIncomeExpenseMember" xlink:label="loc_us-gaap_OtherOperatingIncomeExpenseMember_1914" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_1901" xlink:to="loc_us-gaap_OtherOperatingIncomeExpenseMember_1914" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1902" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1904" xlink:to="loc_dei_LegalEntityAxis_1902" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1915" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1902" xlink:to="loc_dei_EntityDomain_1915" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1915_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1902" xlink:to="loc_dei_EntityDomain_1915_default" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringCostAndReserveAxis" xlink:label="loc_us-gaap_RestructuringCostAndReserveAxis_1903" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1904" xlink:to="loc_us-gaap_RestructuringCostAndReserveAxis_1903" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfRestructuringDomain" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_1908" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_1903" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_1908" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfRestructuringDomain" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_1908_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_1903" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_1908_default" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeSeveranceMember" xlink:label="loc_us-gaap_EmployeeSeveranceMember_1931" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_1908" xlink:to="loc_us-gaap_EmployeeSeveranceMember_1931" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_1907" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1904" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_1907" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_1905" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_1907" xlink:to="loc_us-gaap_SegmentDomain_1905" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_1905_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_1907" xlink:to="loc_us-gaap_SegmentDomain_1905_default" use="optional" order="26" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_CorporateAndEliminationsMember" xlink:label="loc_ter_CorporateAndEliminationsMember_1920" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_1905" xlink:to="loc_ter_CorporateAndEliminationsMember_1920" use="optional" order="27" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SystemsTestGroupMember" xlink:label="loc_ter_SystemsTestGroupMember_1917" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_1905" xlink:to="loc_ter_SystemsTestGroupMember_1917" use="optional" order="28" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_IndustrialAutomationMember" xlink:label="loc_ter_IndustrialAutomationMember_1918" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_1905" xlink:to="loc_ter_IndustrialAutomationMember_1918" use="optional" order="29" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SemiconductorTestMember" xlink:label="loc_ter_SemiconductorTestMember_1916" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_1905" xlink:to="loc_ter_SemiconductorTestMember_1916" use="optional" order="30" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_WirelessTestMember" xlink:label="loc_ter_WirelessTestMember_1919" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_1905" xlink:to="loc_ter_WirelessTestMember_1919" use="optional" order="31" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_RestructuringAndOtherLeaseImpairment" xlink:label="loc_ter_RestructuringAndOtherLeaseImpairment_1924" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1906" xlink:to="loc_ter_RestructuringAndOtherLeaseImpairment_1924" use="optional" order="32" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringSettlementAndImpairmentProvisions" xlink:label="loc_us-gaap_RestructuringSettlementAndImpairmentProvisions_1926" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1906" xlink:to="loc_us-gaap_RestructuringSettlementAndImpairmentProvisions_1926" use="optional" order="33" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_SellingAndAdministrativeForEquityModificationCharge" xlink:label="loc_ter_SellingAndAdministrativeForEquityModificationCharge_511365" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1906" xlink:to="loc_ter_SellingAndAdministrativeForEquityModificationCharge_511365" use="optional" order="34" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LossOnContractTermination" xlink:label="loc_us-gaap_LossOnContractTermination_718757" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1906" xlink:to="loc_us-gaap_LossOnContractTermination_718757" use="optional" order="35" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment" xlink:label="loc_us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment_813495" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1906" xlink:to="loc_us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment_813495" use="optional" order="36" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfRevenuesByCountryDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_1935" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Revenues" xlink:label="loc_us-gaap_Revenues_1940" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_1935" xlink:to="loc_us-gaap_Revenues_1940" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_1936" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_1935" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_1936" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1934" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_1936" xlink:to="loc_dei_LegalEntityAxis_1934" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1939" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1934" xlink:to="loc_dei_EntityDomain_1939" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1939_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1934" xlink:to="loc_dei_EntityDomain_1939_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_StatementGeographicalAxis" xlink:label="loc_srt_StatementGeographicalAxis_1938" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_1936" xlink:to="loc_srt_StatementGeographicalAxis_1938" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_1937" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_1938" xlink:to="loc_srt_SegmentGeographicalDomain_1937" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_1937_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_1938" xlink:to="loc_srt_SegmentGeographicalDomain_1937_default" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_RestOfWorldMember" xlink:label="loc_ter_RestOfWorldMember_1951" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_1937" xlink:to="loc_ter_RestOfWorldMember_1951" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_PH" xlink:label="loc_country_PH_1949" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_1937" xlink:to="loc_country_PH_1949" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_CN" xlink:label="loc_country_CN_1942" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_1937" xlink:to="loc_country_CN_1942" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_SG" xlink:label="loc_country_SG_1948" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_1937" xlink:to="loc_country_SG_1948" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_EuropeMember" xlink:label="loc_srt_EuropeMember_1944" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_1937" xlink:to="loc_srt_EuropeMember_1944" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_JP" xlink:label="loc_country_JP_1946" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_1937" xlink:to="loc_country_JP_1946" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_KR" xlink:label="loc_country_KR_1945" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_1937" xlink:to="loc_country_KR_1945" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_MY" xlink:label="loc_country_MY_1947" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_1937" xlink:to="loc_country_MY_1947" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_TH" xlink:label="loc_country_TH_1950" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_1937" xlink:to="loc_country_TH_1950" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_TW" xlink:label="loc_country_TW_1941" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_1937" xlink:to="loc_country_TW_1941" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US" xlink:label="loc_country_US_1943" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_1937" xlink:to="loc_country_US_1943" use="optional" order="19" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfLongLivedAssetsByGeographicAreaDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_1955" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_1956" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_1955" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_1956" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1954" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_1956" xlink:to="loc_dei_LegalEntityAxis_1954" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1959" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1954" xlink:to="loc_dei_EntityDomain_1959" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1959_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1954" xlink:to="loc_dei_EntityDomain_1959_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_StatementGeographicalAxis" xlink:label="loc_srt_StatementGeographicalAxis_1958" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_1956" xlink:to="loc_srt_StatementGeographicalAxis_1958" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_1957" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_1958" xlink:to="loc_srt_SegmentGeographicalDomain_1957" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_1957_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_1958" xlink:to="loc_srt_SegmentGeographicalDomain_1957_default" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignCountryMember" xlink:label="loc_us-gaap_ForeignCountryMember_1962" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_1957" xlink:to="loc_us-gaap_ForeignCountryMember_1962" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US" xlink:label="loc_country_US_1961" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_1957" xlink:to="loc_country_US_1961" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NoncurrentAssets" xlink:label="loc_us-gaap_NoncurrentAssets_1960" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_1955" xlink:to="loc_us-gaap_NoncurrentAssets_1960" use="optional" order="10" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ScheduleOfLongLivedAssetsByGeographicAreaParentheticalDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_1966" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NoncurrentAssets" xlink:label="loc_us-gaap_NoncurrentAssets_1971" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_1966" xlink:to="loc_us-gaap_NoncurrentAssets_1971" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_1967" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_1966" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_1967" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_StatementGeographicalAxis" xlink:label="loc_srt_StatementGeographicalAxis_1969" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_1967" xlink:to="loc_srt_StatementGeographicalAxis_1969" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_1968" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_1969" xlink:to="loc_srt_SegmentGeographicalDomain_1968" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_1968_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_1969" xlink:to="loc_srt_SegmentGeographicalDomain_1968_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_SG" xlink:label="loc_country_SG_1972" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_1968" xlink:to="loc_country_SG_1972" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1965" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_1967" xlink:to="loc_dei_LegalEntityAxis_1965" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1970" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1965" xlink:to="loc_dei_EntityDomain_1970" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1970_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1965" xlink:to="loc_dei_EntityDomain_1970_default" use="optional" order="9" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/StockRepurchaseProgramAdditionalInformationDetail">
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_StockRepurchaseProgramsLineItems" xlink:label="loc_ter_StockRepurchaseProgramsLineItems_1980" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TreasuryStockShares" xlink:label="loc_us-gaap_TreasuryStockShares_1989" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_StockRepurchaseProgramsLineItems_1980" xlink:to="loc_us-gaap_TreasuryStockShares_1989" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_StockRepurchaseProgramsTable" xlink:label="loc_ter_StockRepurchaseProgramsTable_1981" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ter_StockRepurchaseProgramsLineItems_1980" xlink:to="loc_ter_StockRepurchaseProgramsTable_1981" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_1976" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_StockRepurchaseProgramsTable_1981" xlink:to="loc_srt_RangeAxis_1976" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_1977" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_1976" xlink:to="loc_srt_RangeMember_1977" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_1977_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_1976" xlink:to="loc_srt_RangeMember_1977_default" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_1983" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_1977" xlink:to="loc_srt_MaximumMember_1983" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_StatementScenarioAxis" xlink:label="loc_srt_StatementScenarioAxis_818723" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_StockRepurchaseProgramsTable_1981" xlink:to="loc_srt_StatementScenarioAxis_818723" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ScenarioUnspecifiedDomain" xlink:label="loc_srt_ScenarioUnspecifiedDomain_818724" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementScenarioAxis_818723" xlink:to="loc_srt_ScenarioUnspecifiedDomain_818724" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ScenarioUnspecifiedDomain" xlink:label="loc_srt_ScenarioUnspecifiedDomain_818724_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementScenarioAxis_818723" xlink:to="loc_srt_ScenarioUnspecifiedDomain_818724_default" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TreasuryStockAcquiredAverageCostPerShare" xlink:label="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_1991" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_StockRepurchaseProgramsLineItems_1980" xlink:to="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_1991" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TreasuryStockValue" xlink:label="loc_us-gaap_TreasuryStockValue_1990" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_StockRepurchaseProgramsLineItems_1980" xlink:to="loc_us-gaap_TreasuryStockValue_1990" use="optional" order="11" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/SubsequentEventsAdditionalInformationDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventLineItems" xlink:label="loc_us-gaap_SubsequentEventLineItems_1995" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTable" xlink:label="loc_us-gaap_SubsequentEventTable_1996" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_1995" xlink:to="loc_us-gaap_SubsequentEventTable_1996" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_511222" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_1996" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_511222" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_511223" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_511222" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_511223" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_511223_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_511222" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_511223_default" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1994" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_1996" xlink:to="loc_dei_LegalEntityAxis_1994" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1999" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1994" xlink:to="loc_dei_EntityDomain_1999" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_1999_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1994" xlink:to="loc_dei_EntityDomain_1999_default" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_1997" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_1996" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_1997" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_1998" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_1997" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_1998" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_1998_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_1997" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_1998_default" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_511217" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_1996" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_511217" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_511218" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_511217" xlink:to="loc_us-gaap_SegmentDomain_511218" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_511218_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_511217" xlink:to="loc_us-gaap_SegmentDomain_511218_default" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_TitleOfIndividualAxis" xlink:label="loc_srt_TitleOfIndividualAxis_468958" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_1996" xlink:to="loc_srt_TitleOfIndividualAxis_468958" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_468959" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_TitleOfIndividualAxis_468958" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_468959" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_468959_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_TitleOfIndividualAxis_468958" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_468959_default" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_468964" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_1996" xlink:to="loc_us-gaap_AwardTypeAxis_468964" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_468966" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_468964" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_468966" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_468966_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_468964" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_468966_default" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CollateralAxis" xlink:label="loc_us-gaap_CollateralAxis_683556" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_1996" xlink:to="loc_us-gaap_CollateralAxis_683556" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CollateralDomain" xlink:label="loc_us-gaap_CollateralDomain_683557" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CollateralAxis_683556" xlink:to="loc_us-gaap_CollateralDomain_683557" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CollateralDomain" xlink:label="loc_us-gaap_CollateralDomain_683557_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CollateralAxis_683556" xlink:to="loc_us-gaap_CollateralDomain_683557_default" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DividendPayableDateToBePaidDayMonthAndYear" xlink:label="loc_us-gaap_DividendPayableDateToBePaidDayMonthAndYear_2001" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_1995" xlink:to="loc_us-gaap_DividendPayableDateToBePaidDayMonthAndYear_2001" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DividendsPayableAmountPerShare" xlink:label="loc_us-gaap_DividendsPayableAmountPerShare_2000" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_1995" xlink:to="loc_us-gaap_DividendsPayableAmountPerShare_2000" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DividendsPayableDateOfRecordDayMonthAndYear" xlink:label="loc_us-gaap_DividendsPayableDateOfRecordDayMonthAndYear_2002" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_1995" xlink:to="loc_us-gaap_DividendsPayableDateOfRecordDayMonthAndYear_2002" use="optional" order="25" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ConsolidatedQuarterlyStatementsOfOperationsDetail">
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_QuarterlyFinancialInformationLineItems" xlink:label="loc_ter_QuarterlyFinancialInformationLineItems_2009" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GrossProfit" xlink:label="loc_us-gaap_GrossProfit_2016" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2009" xlink:to="loc_us-gaap_GrossProfit_2016" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_2019" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2009" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_2019" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentIncomeInterest" xlink:label="loc_us-gaap_InvestmentIncomeInterest_2023" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2009" xlink:to="loc_us-gaap_InvestmentIncomeInterest_2023" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockDividendsPerShareDeclared" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_2031" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2009" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_2031" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CostOfGoodsAndServicesSold" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_2015" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2009" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_2015" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EarningsPerShareBasic" xlink:label="loc_us-gaap_EarningsPerShareBasic_2029" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2009" xlink:to="loc_us-gaap_EarningsPerShareBasic_2029" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="loc_us-gaap_EarningsPerShareDiluted_2030" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2009" xlink:to="loc_us-gaap_EarningsPerShareDiluted_2030" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_2025" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2009" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_2025" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_QuarterlyFinancialInformationTable" xlink:label="loc_ter_QuarterlyFinancialInformationTable_2010" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2009" xlink:to="loc_ter_QuarterlyFinancialInformationTable_2010" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2006" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_QuarterlyFinancialInformationTable_2010" xlink:to="loc_dei_LegalEntityAxis_2006" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2011" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2006" xlink:to="loc_dei_EntityDomain_2011" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2011_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2006" xlink:to="loc_dei_EntityDomain_2011_default" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductOrServiceAxis" xlink:label="loc_srt_ProductOrServiceAxis_2007" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_QuarterlyFinancialInformationTable_2010" xlink:to="loc_srt_ProductOrServiceAxis_2007" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_2008" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_2007" xlink:to="loc_srt_ProductsAndServicesDomain_2008" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_2008_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_2007" xlink:to="loc_srt_ProductsAndServicesDomain_2008_default" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProductMember" xlink:label="loc_us-gaap_ProductMember_2012" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_2008" xlink:to="loc_us-gaap_ProductMember_2012" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ServiceMember" xlink:label="loc_us-gaap_ServiceMember_2013" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_2008" xlink:to="loc_us-gaap_ServiceMember_2013" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_2026" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2009" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_2026" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_2027" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2009" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_2027" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestExpense" xlink:label="loc_us-gaap_InterestExpense_2024" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2009" xlink:to="loc_us-gaap_InterestExpense_2024" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_2028" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2009" xlink:to="loc_us-gaap_NetIncomeLoss_2028" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingExpenses" xlink:label="loc_us-gaap_OperatingExpenses_2021" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2009" xlink:to="loc_us-gaap_OperatingExpenses_2021" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaap_OperatingIncomeLoss_2022" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2009" xlink:to="loc_us-gaap_OperatingIncomeLoss_2022" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost_2018" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2009" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost_2018" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringSettlementAndImpairmentProvisions" xlink:label="loc_us-gaap_RestructuringSettlementAndImpairmentProvisions_2020" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2009" xlink:to="loc_us-gaap_RestructuringSettlementAndImpairmentProvisions_2020" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpense" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_2017" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2009" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_2017" use="optional" order="26" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_818745" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2009" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_818745" use="optional" order="27" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ConsolidatedQuarterlyStatementsOfOperationsParentheticalDetail">
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_QuarterlyFinancialInformationLineItems" xlink:label="loc_ter_QuarterlyFinancialInformationLineItems_2041" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanActuarialGainLoss" xlink:label="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss_2059" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2041" xlink:to="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss_2059" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_2051" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2041" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_2051" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_QuarterlyFinancialInformationTable" xlink:label="loc_ter_QuarterlyFinancialInformationTable_2042" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2041" xlink:to="loc_ter_QuarterlyFinancialInformationTable_2042" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LiabilityForCatastropheClaimsByCatastrophicEventAxis" xlink:label="loc_us-gaap_LiabilityForCatastropheClaimsByCatastrophicEventAxis_2038" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_QuarterlyFinancialInformationTable_2042" xlink:to="loc_us-gaap_LiabilityForCatastropheClaimsByCatastrophicEventAxis_2038" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CatastrophicEventDomain" xlink:label="loc_us-gaap_CatastrophicEventDomain_2036" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LiabilityForCatastropheClaimsByCatastrophicEventAxis_2038" xlink:to="loc_us-gaap_CatastrophicEventDomain_2036" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CatastrophicEventDomain" xlink:label="loc_us-gaap_CatastrophicEventDomain_2036_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LiabilityForCatastropheClaimsByCatastrophicEventAxis_2038" xlink:to="loc_us-gaap_CatastrophicEventDomain_2036_default" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_2035" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_QuarterlyFinancialInformationTable_2042" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_2035" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2034" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_2035" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2034" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2034_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_2035" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2034_default" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_UniversalRobotsMember" xlink:label="loc_ter_UniversalRobotsMember_2045" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2034" xlink:to="loc_ter_UniversalRobotsMember_2045" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_MobileIndustrialRobotsApsMember" xlink:label="loc_ter_MobileIndustrialRobotsApsMember_2046" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2034" xlink:to="loc_ter_MobileIndustrialRobotsApsMember_2046" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_AutoguideLlcMember" xlink:label="loc_ter_AutoguideLlcMember_818740" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2034" xlink:to="loc_ter_AutoguideLlcMember_818740" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2037" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_QuarterlyFinancialInformationTable_2042" xlink:to="loc_dei_LegalEntityAxis_2037" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2049" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2037" xlink:to="loc_dei_EntityDomain_2049" use="optional" order="14" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2049_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2037" xlink:to="loc_dei_EntityDomain_2049_default" use="optional" order="15" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_2044" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_QuarterlyFinancialInformationTable_2042" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_2044" use="optional" order="16" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_2043" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_2044" xlink:to="loc_us-gaap_SegmentDomain_2043" use="optional" order="17" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_2043_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_2044" xlink:to="loc_us-gaap_SegmentDomain_2043_default" use="optional" order="18" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_2039" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ter_QuarterlyFinancialInformationTable_2042" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_2039" use="optional" order="19" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LossContingencyNatureDomain" xlink:label="loc_us-gaap_LossContingencyNatureDomain_2040" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_2039" xlink:to="loc_us-gaap_LossContingencyNatureDomain_2040" use="optional" order="20" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LossContingencyNatureDomain" xlink:label="loc_us-gaap_LossContingencyNatureDomain_2040_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_2039" xlink:to="loc_us-gaap_LossContingencyNatureDomain_2040_default" use="optional" order="21" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherAssetImpairmentCharges" xlink:label="loc_us-gaap_OtherAssetImpairmentCharges_2055" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2041" xlink:to="loc_us-gaap_OtherAssetImpairmentCharges_2055" use="optional" order="22" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_2057" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2041" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_2057" use="optional" order="23" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SeveranceCosts1" xlink:label="loc_us-gaap_SeveranceCosts1_2056" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2041" xlink:to="loc_us-gaap_SeveranceCosts1_2056" use="optional" order="24" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment" xlink:label="loc_us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment_818744" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2041" xlink:to="loc_us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment_818744" use="optional" order="25" />
<loc xlink:type="locator" xlink:href="ter-20201231.xsd#ter_ContractTerminationSettlementFee" xlink:label="loc_ter_ContractTerminationSettlementFee_827228" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ter_QuarterlyFinancialInformationLineItems_2041" xlink:to="loc_ter_ContractTerminationSettlementFee_827228" use="optional" order="26" />
</definitionLink>
<definitionLink xlink:type="extended" xlink:role="http://wwww.teradyne.com/role/ValuationAndQualifyingAccountsDetail">
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ValuationAndQualifyingAccountsDisclosureLineItems" xlink:label="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_2065" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationAllowancesAndReservesBalance" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesBalance_2071" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_2065" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesBalance_2071" use="optional" order="1" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_2072" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_2065" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_2072" use="optional" order="2" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts_2073" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_2065" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts_2073" use="optional" order="3" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDeductions" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDeductions_2074" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_2065" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDeductions_2074" use="optional" order="4" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ValuationAndQualifyingAccountsDisclosureTable" xlink:label="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_2066" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_2065" xlink:to="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_2066" xbrldt:contextElement="segment" xbrldt:closed="true" use="optional" order="5" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2062" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_2066" xlink:to="loc_dei_LegalEntityAxis_2062" use="optional" order="6" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2067" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2062" xlink:to="loc_dei_EntityDomain_2067" use="optional" order="7" />
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2067_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2062" xlink:to="loc_dei_EntityDomain_2067_default" use="optional" order="8" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationAllowancesAndReservesTypeAxis" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_2064" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_2066" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_2064" use="optional" order="9" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDomain" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain_2063" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_2064" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain_2063" use="optional" order="10" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDomain" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain_2063_default" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_2064" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain_2063_default" use="optional" order="11" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember" xlink:label="loc_us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember_2070" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_2063" xlink:to="loc_us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember_2070" use="optional" order="12" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryValuationReserveMember" xlink:label="loc_us-gaap_InventoryValuationReserveMember_2069" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_2063" xlink:to="loc_us-gaap_InventoryValuationReserveMember_2069" use="optional" order="13" />
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AllowanceForCreditLossMember" xlink:label="loc_us-gaap_AllowanceForCreditLossMember_2068" />
<definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_2063" xlink:to="loc_us-gaap_AllowanceForCreditLossMember_2068" use="optional" order="14" />
</definitionLink>
</linkbase>
