<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019d2bfc-42d8-7c8e-b969-1817ce6e37c4,g:3adf2637-732d-4369-a0be-f328381fcc82-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link: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"/>
  <link: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"/>
  <link: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"/>
  <link: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"/>
  <link:roleRef roleURI="http://abacusgm.com/role/COVER" xlink:type="simple" xlink:href="abx-20260331.xsd#COVER"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/COVER" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationTable_019d2bfc-44f2-752f-8bd1-af475c596676" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentInformationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_DocumentInformationTable_019d2bfc-44f2-752f-8bd1-af475c596676" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019d2bfc-44f2-766b-a951-9ddb4b8a4fe2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_DocumentInformationTable_019d2bfc-44f2-752f-8bd1-af475c596676" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019d2bfc-44f2-766b-a951-9ddb4b8a4fe2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019d2bfc-44f2-766b-a951-9ddb4b8a4fe2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019d2bfc-44f2-766b-a951-9ddb4b8a4fe2" xlink:to="loc_us-gaap_ClassOfStockDomain_019d2bfc-44f2-766b-a951-9ddb4b8a4fe2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019d2bfc-44f2-7466-ba53-fda3c6d727a9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019d2bfc-44f2-766b-a951-9ddb4b8a4fe2" xlink:to="loc_us-gaap_ClassOfStockDomain_019d2bfc-44f2-7466-ba53-fda3c6d727a9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019d2bfc-44f2-7784-919d-4ff0543ac87c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019d2bfc-44f2-7466-ba53-fda3c6d727a9" xlink:to="loc_us-gaap_CommonStockMember_019d2bfc-44f2-7784-919d-4ff0543ac87c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_FixedUnsecuredNotesMember_019d2bfc-44f2-70be-a557-3c7e538f52fc" xlink:href="abx-20260331.xsd#abx_FixedUnsecuredNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019d2bfc-44f2-7466-ba53-fda3c6d727a9" xlink:to="loc_abx_FixedUnsecuredNotesMember_019d2bfc-44f2-70be-a557-3c7e538f52fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_019d2bfc-44f2-7b48-8775-e300288daca9" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_DocumentType_019d2bfc-44f2-7b48-8775-e300288daca9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentQuarterlyReport_019d9c01-1600-7d5c-be43-8fd6f73ba8f6" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentQuarterlyReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_DocumentQuarterlyReport_019d9c01-1600-7d5c-be43-8fd6f73ba8f6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_019d2bfc-44f2-79aa-986b-66296af0d1e0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentPeriodEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_DocumentPeriodEndDate_019d2bfc-44f2-79aa-986b-66296af0d1e0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport_019d2bfc-44f2-726c-a3f3-1797a590a5b0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentTransitionReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_DocumentTransitionReport_019d2bfc-44f2-726c-a3f3-1797a590a5b0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_019d2bfc-44f2-722c-ab42-8154a02bad7a" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityFileNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_EntityFileNumber_019d2bfc-44f2-722c-ab42-8154a02bad7a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_019d2bfc-44f2-77a5-b0f5-565f7219cfbe" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_EntityRegistrantName_019d2bfc-44f2-77a5-b0f5-565f7219cfbe" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_019d2bfc-44f2-778d-934f-48ca717187df" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_EntityIncorporationStateCountryCode_019d2bfc-44f2-778d-934f-48ca717187df" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_019d2bfc-44f2-7b71-b4a4-831ad2815e67" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_EntityTaxIdentificationNumber_019d2bfc-44f2-7b71-b4a4-831ad2815e67" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_019d2bfc-44f2-7aa8-b8d4-3b12a79abfe3" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressAddressLine1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_EntityAddressAddressLine1_019d2bfc-44f2-7aa8-b8d4-3b12a79abfe3" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_019d2bfc-44f2-724c-949a-470f5f3a4b44" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressCityOrTown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_EntityAddressCityOrTown_019d2bfc-44f2-724c-949a-470f5f3a4b44" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_019d2bfc-44f2-7f64-8d3b-491320c19ba5" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressStateOrProvince"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_EntityAddressStateOrProvince_019d2bfc-44f2-7f64-8d3b-491320c19ba5" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_019d2bfc-44f2-7870-b316-487ef069b588" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressPostalZipCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_EntityAddressPostalZipCode_019d2bfc-44f2-7870-b316-487ef069b588" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_019d2bfc-44f2-71c9-885e-9343a5b99495" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CityAreaCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_CityAreaCode_019d2bfc-44f2-71c9-885e-9343a5b99495" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_019d2bfc-44f2-7d11-b551-6bb5dcfcf9c3" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LocalPhoneNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_LocalPhoneNumber_019d2bfc-44f2-7d11-b551-6bb5dcfcf9c3" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_019d2bfc-44f2-76e0-8186-dcc4f2e0d36c" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_Security12bTitle_019d2bfc-44f2-76e0-8186-dcc4f2e0d36c" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_019d2bfc-44f2-738d-827b-64a52eccaf16" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_TradingSymbol_019d2bfc-44f2-738d-827b-64a52eccaf16" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_019d2bfc-44f2-7975-9bfb-78290f26c37f" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_SecurityExchangeName_019d2bfc-44f2-7975-9bfb-78290f26c37f" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCurrentReportingStatus_019d2bfc-44f2-7874-901a-e79cd585d80b" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCurrentReportingStatus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_EntityCurrentReportingStatus_019d2bfc-44f2-7874-901a-e79cd585d80b" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInteractiveDataCurrent_019d2bfc-44f2-7172-a484-6d46ba5a0780" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityInteractiveDataCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_EntityInteractiveDataCurrent_019d2bfc-44f2-7172-a484-6d46ba5a0780" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFilerCategory_019d2bfc-44f2-7168-bd34-ef46d06ebf09" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityFilerCategory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_EntityFilerCategory_019d2bfc-44f2-7168-bd34-ef46d06ebf09" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitySmallBusiness_019d2bfc-44f2-725b-9c1f-2bd4f7726d2e" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntitySmallBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_EntitySmallBusiness_019d2bfc-44f2-725b-9c1f-2bd4f7726d2e" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_019d2bfc-44f2-7fac-bc0a-1395a772f6d9" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_EntityEmergingGrowthCompany_019d2bfc-44f2-7fac-bc0a-1395a772f6d9" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany_019d2bfc-44f2-7510-a4a4-24c7e1f59144" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityShellCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_EntityShellCompany_019d2bfc-44f2-7510-a4a4-24c7e1f59144" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_019d2bfc-44f2-7e7b-b9d5-b9d918468e21" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_019d2bfc-44f2-7e7b-b9d5-b9d918468e21" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_019d2bfc-44f2-746d-ba27-98cb60e7bf49" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_EntityCentralIndexKey_019d2bfc-44f2-746d-ba27-98cb60e7bf49" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CurrentFiscalYearEndDate_019d2bfc-44f2-7581-b6d1-3737462dbb80" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CurrentFiscalYearEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_CurrentFiscalYearEndDate_019d2bfc-44f2-7581-b6d1-3737462dbb80" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalYearFocus_019d2bfc-44f2-7c74-b37e-d681b4634572" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentFiscalYearFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_DocumentFiscalYearFocus_019d2bfc-44f2-7c74-b37e-d681b4634572" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalPeriodFocus_019d2bfc-44f2-761b-abae-d56e850aafb6" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentFiscalPeriodFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_DocumentFiscalPeriodFocus_019d2bfc-44f2-761b-abae-d56e850aafb6" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_019d9c20-dabd-7eda-80bc-7221afd97ff1" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019d2bfc-44f2-784e-bcfc-1a71788399c0" xlink:to="loc_dei_AmendmentFlag_019d9c20-dabd-7eda-80bc-7221afd97ff1" xlink:type="arc" order="28"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/CONSOLIDATEDBALANCESHEETS" xlink:type="simple" xlink:href="abx-20260331.xsd#CONSOLIDATEDBALANCESHEETS"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/CONSOLIDATEDBALANCESHEETS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7232-a625-65f1675941c0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019d2bfc-44f2-7887-a162-33a9bd35c14e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7232-a625-65f1675941c0" xlink:to="loc_us-gaap_StatementTable_019d2bfc-44f2-7887-a162-33a9bd35c14e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-44f2-7b4b-9de9-9868d2ce3a5e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019d2bfc-44f2-7887-a162-33a9bd35c14e" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-44f2-7b4b-9de9-9868d2ce3a5e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019d2bfc-44f2-7b4b-9de9-9868d2ce3a5e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-44f2-7b4b-9de9-9868d2ce3a5e" xlink:to="loc_us-gaap_RelatedPartyDomain_019d2bfc-44f2-7b4b-9de9-9868d2ce3a5e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019d2bfc-44f2-7c09-b094-40baff8d699a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-44f2-7b4b-9de9-9868d2ce3a5e" xlink:to="loc_us-gaap_RelatedPartyDomain_019d2bfc-44f2-7c09-b094-40baff8d699a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonrelatedPartyMember_019d2bfc-44f2-7e4d-a55c-47fa3758666c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonrelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019d2bfc-44f2-7c09-b094-40baff8d699a" xlink:to="loc_us-gaap_NonrelatedPartyMember_019d2bfc-44f2-7e4d-a55c-47fa3758666c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019d2bfc-44f2-7777-9497-f7d18299ea96" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019d2bfc-44f2-7c09-b094-40baff8d699a" xlink:to="loc_us-gaap_RelatedPartyMember_019d2bfc-44f2-7777-9497-f7d18299ea96" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019d2bfc-44f2-722e-b142-f994e60f3c06" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019d2bfc-44f2-7887-a162-33a9bd35c14e" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019d2bfc-44f2-722e-b142-f994e60f3c06" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019d2bfc-44f2-722e-b142-f994e60f3c06_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019d2bfc-44f2-722e-b142-f994e60f3c06" xlink:to="loc_us-gaap_ClassOfStockDomain_019d2bfc-44f2-722e-b142-f994e60f3c06_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019d2bfc-44f2-70d4-b828-240a0e31ebe7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019d2bfc-44f2-722e-b142-f994e60f3c06" xlink:to="loc_us-gaap_ClassOfStockDomain_019d2bfc-44f2-70d4-b828-240a0e31ebe7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019d2bfc-44f2-7136-b103-078ca1edb6e6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019d2bfc-44f2-70d4-b828-240a0e31ebe7" xlink:to="loc_us-gaap_CommonClassAMember_019d2bfc-44f2-7136-b103-078ca1edb6e6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract_019d2bfc-44f2-7ab8-be7d-897ea1966ec6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7232-a625-65f1675941c0" xlink:to="loc_us-gaap_AssetsAbstract_019d2bfc-44f2-7ab8-be7d-897ea1966ec6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrentAbstract_019d2bfc-44f2-7d8f-a7d4-a5ad1a22258c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019d2bfc-44f2-7ab8-be7d-897ea1966ec6" xlink:to="loc_us-gaap_AssetsCurrentAbstract_019d2bfc-44f2-7d8f-a7d4-a5ad1a22258c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019d2bfc-44f2-78f6-82d0-27acfb404b08" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019d2bfc-44f2-7d8f-a7d4-a5ad1a22258c" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019d2bfc-44f2-78f6-82d0-27acfb404b08" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_019d2bfc-44f2-7b3d-9287-f91aba493b2a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019d2bfc-44f2-7d8f-a7d4-a5ad1a22258c" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_019d2bfc-44f2-7b3d-9287-f91aba493b2a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxesReceivable_019d2bfc-44f2-7fcf-8850-32270ba90eef" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxesReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019d2bfc-44f2-7d8f-a7d4-a5ad1a22258c" xlink:to="loc_us-gaap_IncomeTaxesReceivable_019d2bfc-44f2-7fcf-8850-32270ba90eef" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_019d2bfc-44f2-751a-b074-fbb89f3b3bd1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019d2bfc-44f2-7d8f-a7d4-a5ad1a22258c" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_019d2bfc-44f2-751a-b074-fbb89f3b3bd1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_019d2bfc-44f2-73b9-b3ae-703aa1ec77d4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019d2bfc-44f2-7d8f-a7d4-a5ad1a22258c" xlink:to="loc_us-gaap_AssetsCurrent_019d2bfc-44f2-73b9-b3ae-703aa1ec77d4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_019d2bfc-44f2-706a-9280-066e1ef82333" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019d2bfc-44f2-7ab8-be7d-897ea1966ec6" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_019d2bfc-44f2-706a-9280-066e1ef82333" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_019d2bfc-44f2-782e-8297-ae5bdc55ac27" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019d2bfc-44f2-7ab8-be7d-897ea1966ec6" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_019d2bfc-44f2-782e-8297-ae5bdc55ac27" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019d2bfc-44f2-7236-becf-2a3da7b3e587" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019d2bfc-44f2-7ab8-be7d-897ea1966ec6" xlink:to="loc_us-gaap_Goodwill_019d2bfc-44f2-7236-becf-2a3da7b3e587" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_019d2bfc-44f2-7b03-8525-eb630bbc6d0f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019d2bfc-44f2-7ab8-be7d-897ea1966ec6" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_019d2bfc-44f2-7b03-8525-eb630bbc6d0f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetNoncurrent_019d2bfc-44f2-7ef2-a005-ca1b911b3ca4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableNetNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019d2bfc-44f2-7ab8-be7d-897ea1966ec6" xlink:to="loc_us-gaap_AccountsReceivableNetNoncurrent_019d2bfc-44f2-7ef2-a005-ca1b911b3ca4" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LifeSettlementContractsFairValueMethodCarryingAmount_019d2bfc-44f2-7723-8a16-69973d41051f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LifeSettlementContractsFairValueMethodCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019d2bfc-44f2-7ab8-be7d-897ea1966ec6" xlink:to="loc_us-gaap_LifeSettlementContractsFairValueMethodCarryingAmount_019d2bfc-44f2-7723-8a16-69973d41051f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LifeSettlementContractsInvestmentMethodCarryingAmount_019d2bfc-44f2-79b0-a398-1940d750c94e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LifeSettlementContractsInvestmentMethodCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019d2bfc-44f2-7ab8-be7d-897ea1966ec6" xlink:to="loc_us-gaap_LifeSettlementContractsInvestmentMethodCarryingAmount_019d2bfc-44f2-79b0-a398-1940d750c94e" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent_019d2bfc-44f2-73a3-842a-32e599e5e61b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019d2bfc-44f2-7ab8-be7d-897ea1966ec6" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent_019d2bfc-44f2-73a3-842a-32e599e5e61b" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFVNINoncurrent_019d2bfc-44f2-7348-9367-6dbb72dceefa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquitySecuritiesFVNINoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019d2bfc-44f2-7ab8-be7d-897ea1966ec6" xlink:to="loc_us-gaap_EquitySecuritiesFVNINoncurrent_019d2bfc-44f2-7348-9367-6dbb72dceefa" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_019d2bfc-44f2-7748-be86-d3cfcdff57cf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019d2bfc-44f2-7ab8-be7d-897ea1966ec6" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_019d2bfc-44f2-7748-be86-d3cfcdff57cf" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019d2bfc-44f2-73e6-94ec-d0a289326abf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019d2bfc-44f2-7ab8-be7d-897ea1966ec6" xlink:to="loc_us-gaap_Assets_019d2bfc-44f2-73e6-94ec-d0a289326abf" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019d2bfc-44f2-7d91-8c45-3d8ea14f46e8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7232-a625-65f1675941c0" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019d2bfc-44f2-7d91-8c45-3d8ea14f46e8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract_019d2bfc-44f2-7664-a9b2-efa9d3f4a931" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019d2bfc-44f2-7d91-8c45-3d8ea14f46e8" xlink:to="loc_us-gaap_LiabilitiesCurrentAbstract_019d2bfc-44f2-7664-a9b2-efa9d3f4a931" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LongTermDebtCurrentMaturitiesFairValue_019d2bfc-44f2-76e0-bf76-f2898b485c28" xlink:href="abx-20260331.xsd#abx_LongTermDebtCurrentMaturitiesFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019d2bfc-44f2-7664-a9b2-efa9d3f4a931" xlink:to="loc_abx_LongTermDebtCurrentMaturitiesFairValue_019d2bfc-44f2-76e0-bf76-f2898b485c28" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LongTermDebtCurrentMaturitiesReportedValue_019d2bfc-44f2-7293-9cd2-b4a5702985af" xlink:href="abx-20260331.xsd#abx_LongTermDebtCurrentMaturitiesReportedValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019d2bfc-44f2-7664-a9b2-efa9d3f4a931" xlink:to="loc_abx_LongTermDebtCurrentMaturitiesReportedValue_019d2bfc-44f2-7293-9cd2-b4a5702985af" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent_019d2bfc-44f2-720d-9130-335ad56dc2c9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019d2bfc-44f2-7664-a9b2-efa9d3f4a931" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent_019d2bfc-44f2-720d-9130-335ad56dc2c9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityCurrent_019d2bfc-44f2-7bd8-983c-f349e5a3e63d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019d2bfc-44f2-7664-a9b2-efa9d3f4a931" xlink:to="loc_us-gaap_OperatingLeaseLiabilityCurrent_019d2bfc-44f2-7bd8-983c-f349e5a3e63d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCurrent_019d2bfc-44f2-77de-81d3-52725a36fdfe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019d2bfc-44f2-7664-a9b2-efa9d3f4a931" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityCurrent_019d2bfc-44f2-77de-81d3-52725a36fdfe" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_AccruedTransactionCostsCurrent_019d2bfc-44f2-7f4d-aceb-fe9525e15002" xlink:href="abx-20260331.xsd#abx_AccruedTransactionCostsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019d2bfc-44f2-7664-a9b2-efa9d3f4a931" xlink:to="loc_abx_AccruedTransactionCostsCurrent_019d2bfc-44f2-7f4d-aceb-fe9525e15002" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesCurrent_019d2bfc-44f2-7ab1-8b93-705b7337d47f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019d2bfc-44f2-7664-a9b2-efa9d3f4a931" xlink:to="loc_us-gaap_OtherLiabilitiesCurrent_019d2bfc-44f2-7ab1-8b93-705b7337d47f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedIncomeTaxesCurrent_019d2bfc-44f2-7065-99e2-d192cbf397f9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedIncomeTaxesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019d2bfc-44f2-7664-a9b2-efa9d3f4a931" xlink:to="loc_us-gaap_AccruedIncomeTaxesCurrent_019d2bfc-44f2-7065-99e2-d192cbf397f9" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_019d2bfc-44f2-74a3-a6c0-28a36f513123" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019d2bfc-44f2-7664-a9b2-efa9d3f4a931" xlink:to="loc_us-gaap_LiabilitiesCurrent_019d2bfc-44f2-74a3-a6c0-28a36f513123" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LongTermDebtExcludingCurrentMaturitiesReportedValue_019d2bfc-44f2-7f4e-a099-daaa0d1ddcc5" xlink:href="abx-20260331.xsd#abx_LongTermDebtExcludingCurrentMaturitiesReportedValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019d2bfc-44f2-7d91-8c45-3d8ea14f46e8" xlink:to="loc_abx_LongTermDebtExcludingCurrentMaturitiesReportedValue_019d2bfc-44f2-7f4e-a099-daaa0d1ddcc5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtFairValue_019d2bfc-44f2-757f-9f97-ce86eaebbd2b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019d2bfc-44f2-7d91-8c45-3d8ea14f46e8" xlink:to="loc_us-gaap_LongTermDebtFairValue_019d2bfc-44f2-757f-9f97-ce86eaebbd2b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_RetrocessionFeesPayableNoncurrent_019d2bfc-44f2-754a-b667-c19212ea7b0f" xlink:href="abx-20260331.xsd#abx_RetrocessionFeesPayableNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019d2bfc-44f2-7d91-8c45-3d8ea14f46e8" xlink:to="loc_abx_RetrocessionFeesPayableNoncurrent_019d2bfc-44f2-754a-b667-c19212ea7b0f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_019d2bfc-44f2-7aba-8bd7-74e049034b1a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019d2bfc-44f2-7d91-8c45-3d8ea14f46e8" xlink:to="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_019d2bfc-44f2-7aba-8bd7-74e049034b1a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_019d2bfc-44f2-7502-9a85-b294e05d62f0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019d2bfc-44f2-7d91-8c45-3d8ea14f46e8" xlink:to="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_019d2bfc-44f2-7502-9a85-b294e05d62f0" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_WarrantLiabilitiesNoncurrent_019d2bfc-44f2-7d3a-ab47-2ee4f2d12a5c" xlink:href="abx-20260331.xsd#abx_WarrantLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019d2bfc-44f2-7d91-8c45-3d8ea14f46e8" xlink:to="loc_abx_WarrantLiabilitiesNoncurrent_019d2bfc-44f2-7d3a-ab47-2ee4f2d12a5c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019d2bfc-44f2-7c43-b0a0-8ce3a0396672" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019d2bfc-44f2-7d91-8c45-3d8ea14f46e8" xlink:to="loc_us-gaap_Liabilities_019d2bfc-44f2-7c43-b0a0-8ce3a0396672" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_019d2bfc-44f2-7754-a0e4-85f1662c6b68" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019d2bfc-44f2-7d91-8c45-3d8ea14f46e8" xlink:to="loc_us-gaap_CommitmentsAndContingencies_019d2bfc-44f2-7754-a0e4-85f1662c6b68" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityAbstract_019d2bfc-44f2-7e91-968d-fdd2d54faab4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019d2bfc-44f2-7d91-8c45-3d8ea14f46e8" xlink:to="loc_us-gaap_TemporaryEquityAbstract_019d2bfc-44f2-7e91-968d-fdd2d54faab4" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityCarryingAmountAttributableToParent_019d2bfc-44f2-796d-b19d-3f86d0fc7484" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityCarryingAmountAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TemporaryEquityAbstract_019d2bfc-44f2-7e91-968d-fdd2d54faab4" xlink:to="loc_us-gaap_TemporaryEquityCarryingAmountAttributableToParent_019d2bfc-44f2-796d-b19d-3f86d0fc7484" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_019d2bfc-44f2-704e-89c3-f535ea75a442" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019d2bfc-44f2-7d91-8c45-3d8ea14f46e8" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_019d2bfc-44f2-704e-89c3-f535ea75a442" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockValue_019d2bfc-44f2-7eb5-9c34-03d1259d2f51" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_019d2bfc-44f2-704e-89c3-f535ea75a442" xlink:to="loc_us-gaap_PreferredStockValue_019d2bfc-44f2-7eb5-9c34-03d1259d2f51" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_019d2bfc-44f2-71d1-ad4d-423baa694989" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_019d2bfc-44f2-704e-89c3-f535ea75a442" xlink:to="loc_us-gaap_CommonStockValue_019d2bfc-44f2-71d1-ad4d-423baa694989" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonValue_019d2bfc-44f2-7ce0-9761-0404b90f61c9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockCommonValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_019d2bfc-44f2-704e-89c3-f535ea75a442" xlink:to="loc_us-gaap_TreasuryStockCommonValue_019d2bfc-44f2-7ce0-9761-0404b90f61c9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapital_019d2bfc-44f2-7c34-83fd-abc92c02c10a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_019d2bfc-44f2-704e-89c3-f535ea75a442" xlink:to="loc_us-gaap_AdditionalPaidInCapital_019d2bfc-44f2-7c34-83fd-abc92c02c10a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019d2bfc-44f2-74ac-8647-9d0cf1b427a0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_019d2bfc-44f2-704e-89c3-f535ea75a442" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019d2bfc-44f2-74ac-8647-9d0cf1b427a0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterest_019d2bfc-44f2-77f2-8740-39c2beb6fd20" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_019d2bfc-44f2-704e-89c3-f535ea75a442" xlink:to="loc_us-gaap_MinorityInterest_019d2bfc-44f2-77f2-8740-39c2beb6fd20" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019d2bfc-44f2-7610-974d-c526988b0a5b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_019d2bfc-44f2-704e-89c3-f535ea75a442" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019d2bfc-44f2-7610-974d-c526988b0a5b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_019d2bfc-44f2-7bf1-bf48-adbbdbc3693b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019d2bfc-44f2-7d91-8c45-3d8ea14f46e8" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_019d2bfc-44f2-7bf1-bf48-adbbdbc3693b" xlink:type="arc" order="12"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/UNAUDITEDCONSOLIDATEDSTATEMENTSOFOPERATIONSANDCOMPREHENSIVEINCOME" xlink:type="simple" xlink:href="abx-20260331.xsd#UNAUDITEDCONSOLIDATEDSTATEMENTSOFOPERATIONSANDCOMPREHENSIVEINCOME"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/UNAUDITEDCONSOLIDATEDSTATEMENTSOFOPERATIONSANDCOMPREHENSIVEINCOME" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7e40-8357-ab99f4d87a67" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019d2bfc-44f2-7a6e-a4b5-448dd6ccbe55" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7e40-8357-ab99f4d87a67" xlink:to="loc_us-gaap_StatementTable_019d2bfc-44f2-7a6e-a4b5-448dd6ccbe55" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019d2bfc-44f2-7e3e-8eb3-b300bbc38a5a" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019d2bfc-44f2-7a6e-a4b5-448dd6ccbe55" xlink:to="loc_srt_ProductOrServiceAxis_019d2bfc-44f2-7e3e-8eb3-b300bbc38a5a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019d2bfc-44f2-7e3e-8eb3-b300bbc38a5a_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019d2bfc-44f2-7e3e-8eb3-b300bbc38a5a" xlink:to="loc_srt_ProductsAndServicesDomain_019d2bfc-44f2-7e3e-8eb3-b300bbc38a5a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019d2bfc-44f2-7da8-a4b8-7b834a635c95" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019d2bfc-44f2-7e3e-8eb3-b300bbc38a5a" xlink:to="loc_srt_ProductsAndServicesDomain_019d2bfc-44f2-7da8-a4b8-7b834a635c95" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetManagement1Member_019d2bfc-44f2-7089-8244-39ae74e5a93c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetManagement1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019d2bfc-44f2-7da8-a4b8-7b834a635c95" xlink:to="loc_us-gaap_AssetManagement1Member_019d2bfc-44f2-7089-8244-39ae74e5a93c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSolutionsMember_019d2bfc-44f2-7e73-b285-6d772ed767a1" xlink:href="abx-20260331.xsd#abx_LifeSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019d2bfc-44f2-7da8-a4b8-7b834a635c95" xlink:to="loc_abx_LifeSolutionsMember_019d2bfc-44f2-7e73-b285-6d772ed767a1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TechnologyServiceMember_019d2bfc-44f2-7fb7-8264-c2e3f8315ad9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TechnologyServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019d2bfc-44f2-7da8-a4b8-7b834a635c95" xlink:to="loc_us-gaap_TechnologyServiceMember_019d2bfc-44f2-7fb7-8264-c2e3f8315ad9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-44f2-7c2e-b4f3-ea968b1e3ad7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019d2bfc-44f2-7a6e-a4b5-448dd6ccbe55" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-44f2-7c2e-b4f3-ea968b1e3ad7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019d2bfc-44f2-7c2e-b4f3-ea968b1e3ad7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-44f2-7c2e-b4f3-ea968b1e3ad7" xlink:to="loc_us-gaap_RelatedPartyDomain_019d2bfc-44f2-7c2e-b4f3-ea968b1e3ad7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019d2bfc-44f2-7309-bbe2-0acc022a0d1a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-44f2-7c2e-b4f3-ea968b1e3ad7" xlink:to="loc_us-gaap_RelatedPartyDomain_019d2bfc-44f2-7309-bbe2-0acc022a0d1a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonrelatedPartyMember_019d2bfc-44f2-7ab4-bdf8-51d2ee535469" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonrelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019d2bfc-44f2-7309-bbe2-0acc022a0d1a" xlink:to="loc_us-gaap_NonrelatedPartyMember_019d2bfc-44f2-7ab4-bdf8-51d2ee535469" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019d2bfc-44f2-7f83-9459-31a4b1051004" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019d2bfc-44f2-7309-bbe2-0acc022a0d1a" xlink:to="loc_us-gaap_RelatedPartyMember_019d2bfc-44f2-7f83-9459-31a4b1051004" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesAbstract_019d2bfc-44f2-71d6-9f32-28520f8fa21a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenuesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7e40-8357-ab99f4d87a67" xlink:to="loc_us-gaap_RevenuesAbstract_019d2bfc-44f2-71d6-9f32-28520f8fa21a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019d2bfc-44f2-71e8-be10-0e7dbfc6dcd5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_019d2bfc-44f2-71d6-9f32-28520f8fa21a" xlink:to="loc_us-gaap_Revenues_019d2bfc-44f2-71e8-be10-0e7dbfc6dcd5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfRevenueAbstract_019d2bfc-44f2-70eb-bbf9-55473c7c8768" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfRevenueAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7e40-8357-ab99f4d87a67" xlink:to="loc_us-gaap_CostOfRevenueAbstract_019d2bfc-44f2-70eb-bbf9-55473c7c8768" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfRevenue_019d2bfc-44f2-79ec-9bb1-a1bc18fbe79e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfRevenueAbstract_019d2bfc-44f2-70eb-bbf9-55473c7c8768" xlink:to="loc_us-gaap_CostOfRevenue_019d2bfc-44f2-79ec-9bb1-a1bc18fbe79e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_019d2bfc-44f2-7037-8222-6aa6620a9a96" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GrossProfit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7e40-8357-ab99f4d87a67" xlink:to="loc_us-gaap_GrossProfit_019d2bfc-44f2-7037-8222-6aa6620a9a96" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpensesAbstract_019d2bfc-44f2-7dcd-bcdf-1bd72f27c461" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7e40-8357-ab99f4d87a67" xlink:to="loc_us-gaap_OperatingExpensesAbstract_019d2bfc-44f2-7dcd-bcdf-1bd72f27c461" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingAndMarketingExpense_019d2bfc-44f2-7438-8ee0-3bd2d5ec6962" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SellingAndMarketingExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019d2bfc-44f2-7dcd-bcdf-1bd72f27c461" xlink:to="loc_us-gaap_SellingAndMarketingExpense_019d2bfc-44f2-7438-8ee0-3bd2d5ec6962" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_019d2bfc-44f2-7d70-add9-52da8a3bd8a8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019d2bfc-44f2-7dcd-bcdf-1bd72f27c461" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_019d2bfc-44f2-7d70-add9-52da8a3bd8a8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_019d2bfc-44f2-7a06-ab2b-f1dda88de76f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019d2bfc-44f2-7dcd-bcdf-1bd72f27c461" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_019d2bfc-44f2-7a06-ab2b-f1dda88de76f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss_019d2bfc-44f2-7a8d-bf59-27ad7b2430bc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019d2bfc-44f2-7dcd-bcdf-1bd72f27c461" xlink:to="loc_us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss_019d2bfc-44f2-7a8d-bf59-27ad7b2430bc" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationAndAmortization_019d2bfc-44f2-7632-93c3-a0307128c1cc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019d2bfc-44f2-7dcd-bcdf-1bd72f27c461" xlink:to="loc_us-gaap_DepreciationAndAmortization_019d2bfc-44f2-7632-93c3-a0307128c1cc" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_019d2bfc-44f2-77ef-9d6f-2f35b2b7c464" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7e40-8357-ab99f4d87a67" xlink:to="loc_us-gaap_OperatingExpenses_019d2bfc-44f2-77ef-9d6f-2f35b2b7c464" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019d2bfc-44f2-7385-ae47-2bd064bb92a0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7e40-8357-ab99f4d87a67" xlink:to="loc_us-gaap_OperatingIncomeLoss_019d2bfc-44f2-7385-ae47-2bd064bb92a0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019d2bfc-44f2-7c79-9795-8e23c3a745e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonoperatingIncomeExpenseAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7e40-8357-ab99f4d87a67" xlink:to="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019d2bfc-44f2-7c79-9795-8e23c3a745e7" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAdjustmentOfWarrants_019d2bfc-44f2-74c1-8dbb-ae373785f520" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAdjustmentOfWarrants"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019d2bfc-44f2-7c79-9795-8e23c3a745e7" xlink:to="loc_us-gaap_FairValueAdjustmentOfWarrants_019d2bfc-44f2-74c1-8dbb-ae373785f520" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_019d2bfc-44f2-7572-a6ea-a928504a8b67" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019d2bfc-44f2-7c79-9795-8e23c3a745e7" xlink:to="loc_us-gaap_InterestExpenseNonoperating_019d2bfc-44f2-7572-a6ea-a928504a8b67" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeInterest_019d2bfc-44f2-78b5-af0b-3be0a74872c0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentIncomeInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019d2bfc-44f2-7c79-9795-8e23c3a745e7" xlink:to="loc_us-gaap_InvestmentIncomeInterest_019d2bfc-44f2-78b5-af0b-3be0a74872c0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019d2bfc-44f2-75b4-b949-c1714a4463a6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019d2bfc-44f2-7c79-9795-8e23c3a745e7" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_019d2bfc-44f2-75b4-b949-c1714a4463a6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_019d2bfc-44f2-7ff7-8bf0-15f07d25db46" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7e40-8357-ab99f4d87a67" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_019d2bfc-44f2-7ff7-8bf0-15f07d25db46" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossIncludingPortionAttributableToNoncontrollingInterest_019d2bfc-44f2-74bc-8ab2-04f13bba8209" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7e40-8357-ab99f4d87a67" xlink:to="loc_us-gaap_IncomeLossIncludingPortionAttributableToNoncontrollingInterest_019d2bfc-44f2-74bc-8ab2-04f13bba8209" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019d2bfc-44f2-7ef7-b5cf-941072d12045" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7e40-8357-ab99f4d87a67" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019d2bfc-44f2-7ef7-b5cf-941072d12045" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019d2bfc-44f2-7971-b621-981e4bb000bf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7e40-8357-ab99f4d87a67" xlink:to="loc_us-gaap_ProfitLoss_019d2bfc-44f2-7971-b621-981e4bb000bf" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019d2bfc-44f2-74ca-b14d-327fcc0b22f5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7e40-8357-ab99f4d87a67" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019d2bfc-44f2-74ca-b14d-327fcc0b22f5" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019d2bfc-44f2-7ea4-a393-b9ad6e0b2e7a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7e40-8357-ab99f4d87a67" xlink:to="loc_us-gaap_NetIncomeLoss_019d2bfc-44f2-7ea4-a393-b9ad6e0b2e7a" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareAbstract_019d2bfc-44f2-710c-87f9-d3edef418e13" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7e40-8357-ab99f4d87a67" xlink:to="loc_us-gaap_EarningsPerShareAbstract_019d2bfc-44f2-710c-87f9-d3edef418e13" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_019d2bfc-44f2-7c00-95ae-a8bfd7e6b496" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_019d2bfc-44f2-710c-87f9-d3edef418e13" xlink:to="loc_us-gaap_EarningsPerShareBasic_019d2bfc-44f2-7c00-95ae-a8bfd7e6b496" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_019d2bfc-44f2-771b-9b55-ebaa8fd7e994" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_019d2bfc-44f2-710c-87f9-d3edef418e13" xlink:to="loc_us-gaap_EarningsPerShareDiluted_019d2bfc-44f2-771b-9b55-ebaa8fd7e994" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019d2bfc-44f2-71da-bf33-9264489b302b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_019d2bfc-44f2-710c-87f9-d3edef418e13" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019d2bfc-44f2-71da-bf33-9264489b302b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019d2bfc-44f2-72e3-a320-84f38145ca67" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_019d2bfc-44f2-710c-87f9-d3edef418e13" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019d2bfc-44f2-72e3-a320-84f38145ca67" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019d2bfc-44f2-7a75-a348-92a7d7566df2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_019d2bfc-44f2-7357-b08d-222aa6260fe4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7e40-8357-ab99f4d87a67" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_019d2bfc-44f2-7357-b08d-222aa6260fe4" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest_019d2bfc-44f2-758d-86d0-74692ef489c4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7e40-8357-ab99f4d87a67" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest_019d2bfc-44f2-758d-86d0-74692ef489c4" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_019d2bfc-44f2-78e1-b4ca-4bcad3a6b7aa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComprehensiveIncomeNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-7e40-8357-ab99f4d87a67" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTax_019d2bfc-44f2-78e1-b4ca-4bcad3a6b7aa" xlink:type="arc" order="17"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/CONSOLIDATEDSTATEMENTSOFCHANGESINSTOCKHOLDERSEQUITY" xlink:type="simple" xlink:href="abx-20260331.xsd#CONSOLIDATEDSTATEMENTSOFCHANGESINSTOCKHOLDERSEQUITY"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/CONSOLIDATEDSTATEMENTSOFCHANGESINSTOCKHOLDERSEQUITY" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019d2bfc-44f2-70f7-af02-0153842fb64a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019d2bfc-44f2-7ce0-bb9c-1c6b3329327c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-70f7-af02-0153842fb64a" xlink:to="loc_us-gaap_StatementTable_019d2bfc-44f2-7ce0-bb9c-1c6b3329327c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019d2bfc-44f2-7577-a39e-a3500af8f0d1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019d2bfc-44f2-7ce0-bb9c-1c6b3329327c" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019d2bfc-44f2-7577-a39e-a3500af8f0d1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019d2bfc-44f2-7577-a39e-a3500af8f0d1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019d2bfc-44f2-7577-a39e-a3500af8f0d1" xlink:to="loc_us-gaap_EquityComponentDomain_019d2bfc-44f2-7577-a39e-a3500af8f0d1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019d2bfc-44f2-7774-a49f-e6ecb902d5ab" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019d2bfc-44f2-7577-a39e-a3500af8f0d1" xlink:to="loc_us-gaap_EquityComponentDomain_019d2bfc-44f2-7774-a49f-e6ecb902d5ab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019d2bfc-44f2-73a9-9db2-308e188cbb6e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019d2bfc-44f2-7774-a49f-e6ecb902d5ab" xlink:to="loc_us-gaap_CommonStockMember_019d2bfc-44f2-73a9-9db2-308e188cbb6e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonMember_019d2bfc-44f2-7876-8e39-0a6a5307c2c4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockCommonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019d2bfc-44f2-7774-a49f-e6ecb902d5ab" xlink:to="loc_us-gaap_TreasuryStockCommonMember_019d2bfc-44f2-7876-8e39-0a6a5307c2c4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_019d2bfc-44f2-7489-b54e-0d2ccac37637" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019d2bfc-44f2-7774-a49f-e6ecb902d5ab" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_019d2bfc-44f2-7489-b54e-0d2ccac37637" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_019d2bfc-44f2-72cc-9060-7d1523b85186" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019d2bfc-44f2-7774-a49f-e6ecb902d5ab" xlink:to="loc_us-gaap_RetainedEarningsMember_019d2bfc-44f2-72cc-9060-7d1523b85186" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_019d2bfc-44f2-761e-ad44-0a1740966d18" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019d2bfc-44f2-7774-a49f-e6ecb902d5ab" xlink:to="loc_us-gaap_NoncontrollingInterestMember_019d2bfc-44f2-761e-ad44-0a1740966d18" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019d2bfc-44f2-790a-ba9f-288ba09620e6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019d2bfc-44f2-7ce0-bb9c-1c6b3329327c" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019d2bfc-44f2-790a-ba9f-288ba09620e6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019d2bfc-44f2-790a-ba9f-288ba09620e6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019d2bfc-44f2-790a-ba9f-288ba09620e6" xlink:to="loc_us-gaap_ClassOfStockDomain_019d2bfc-44f2-790a-ba9f-288ba09620e6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019d2bfc-44f2-70e8-b45d-997c400e471f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019d2bfc-44f2-790a-ba9f-288ba09620e6" xlink:to="loc_us-gaap_ClassOfStockDomain_019d2bfc-44f2-70e8-b45d-997c400e471f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019d2bfc-44f2-7eb3-93d7-1b6b7809f3e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019d2bfc-44f2-70e8-b45d-997c400e471f" xlink:to="loc_us-gaap_CommonClassAMember_019d2bfc-44f2-7eb3-93d7-1b6b7809f3e7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_019d2bfc-44f2-7b84-9d73-472510416d68" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInTemporaryEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-70f7-af02-0153842fb64a" xlink:to="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_019d2bfc-44f2-7b84-9d73-472510416d68" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquitySharesOutstanding_019d2bfc-44f2-7833-a33d-c7c6b430de1b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquitySharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_019d2bfc-44f2-7b84-9d73-472510416d68" xlink:to="loc_us-gaap_TemporaryEquitySharesOutstanding_019d2bfc-44f2-7833-a33d-c7c6b430de1b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityCarryingAmountAttributableToParent_019d2bfc-44f2-78af-9f87-a4a5ee77fcd9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityCarryingAmountAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_019d2bfc-44f2-7b84-9d73-472510416d68" xlink:to="loc_us-gaap_TemporaryEquityCarryingAmountAttributableToParent_019d2bfc-44f2-78af-9f87-a4a5ee77fcd9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_TemporaryEquityStockIssuedDuringPeriodSharesNewIssues_019d2bfc-44f2-7778-a937-2648e8544932" xlink:href="abx-20260331.xsd#abx_TemporaryEquityStockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_019d2bfc-44f2-7b84-9d73-472510416d68" xlink:to="loc_abx_TemporaryEquityStockIssuedDuringPeriodSharesNewIssues_019d2bfc-44f2-7778-a937-2648e8544932" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityStockIssuedDuringPeriodValueNewIssues_019d2bfc-44f2-76df-b147-3420db5a0201" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityStockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_019d2bfc-44f2-7b84-9d73-472510416d68" xlink:to="loc_us-gaap_TemporaryEquityStockIssuedDuringPeriodValueNewIssues_019d2bfc-44f2-76df-b147-3420db5a0201" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquitySharesOutstanding_019d2bfc-44f2-7d14-a1cb-2c81f0beb079" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquitySharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityCarryingAmountAttributableToParent_019d2bfc-44f2-7f35-88a3-163cd278d50f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityCarryingAmountAttributableToParent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019d2bfc-44f2-7b18-b433-b99845ee7891" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-70f7-af02-0153842fb64a" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019d2bfc-44f2-7b18-b433-b99845ee7891" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019d2bfc-44f2-7926-bec5-8b107a1386f5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019d2bfc-44f2-7b18-b433-b99845ee7891" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_019d2bfc-44f2-7926-bec5-8b107a1386f5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019d2bfc-44f2-767a-ae16-58c36055d998" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019d2bfc-44f2-7b18-b433-b99845ee7891" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019d2bfc-44f2-767a-ae16-58c36055d998" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_019d2bfc-44f2-7827-8875-72afc9d037f8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockCommonShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019d2bfc-44f2-7b18-b433-b99845ee7891" xlink:to="loc_us-gaap_TreasuryStockCommonShares_019d2bfc-44f2-7827-8875-72afc9d037f8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_019dd3da-8e3a-74a7-a4ee-9838b4c496d9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockSharesAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019d2bfc-44f2-7b18-b433-b99845ee7891" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_019dd3da-8e3a-74a7-a4ee-9838b4c496d9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_019d2bfc-44f2-76f7-9ac2-31f8abd480a8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019d2bfc-44f2-7b18-b433-b99845ee7891" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_019d2bfc-44f2-76f7-9ac2-31f8abd480a8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_019d2bfc-44f2-7853-8a0a-80ffaca7098a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019d2bfc-44f2-7b18-b433-b99845ee7891" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_019d2bfc-44f2-7853-8a0a-80ffaca7098a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_019d2bfc-44f2-76ba-a961-a009c7d6b827" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019d2bfc-44f2-7b18-b433-b99845ee7891" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_019d2bfc-44f2-76ba-a961-a009c7d6b827" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPreferredStock_019dd3dd-cd66-7493-9e36-1b6e453228de" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DividendsPreferredStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019d2bfc-44f2-7b18-b433-b99845ee7891" xlink:to="loc_us-gaap_DividendsPreferredStock_019dd3dd-cd66-7493-9e36-1b6e453228de" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_019d2bfc-44f2-72ef-aa23-9fa506d33b31" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019d2bfc-44f2-7b18-b433-b99845ee7891" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_019d2bfc-44f2-72ef-aa23-9fa506d33b31" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities_019d2bfc-44f2-73eb-b7de-1a313c25282f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019d2bfc-44f2-7b18-b433-b99845ee7891" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities_019d2bfc-44f2-73eb-b7de-1a313c25282f" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts_019d2bfc-44f2-7b02-bc3a-6d8db7e6cb95" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019d2bfc-44f2-7b18-b433-b99845ee7891" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts_019d2bfc-44f2-7b02-bc3a-6d8db7e6cb95" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019d2bfc-44f2-7050-900e-71bb526b31ac" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019d2bfc-44f2-7b18-b433-b99845ee7891" xlink:to="loc_us-gaap_ProfitLoss_019d2bfc-44f2-7050-900e-71bb526b31ac" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019d2bfc-44f2-7140-a7dd-345f29d265e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019d2bfc-44f2-7ac1-9baa-524c4fd31a86" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_019d2bfc-44f2-78aa-8e8c-438c0179f8af" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockCommonShares"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS" xlink:type="simple" xlink:href="abx-20260331.xsd#CONSOLIDATEDSTATEMENTSOFCASHFLOWS"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019d2bfc-44f2-72f4-a71e-97f8b1749e6d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019d2bfc-44f2-7e66-8165-4bfe4121c8cd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-72f4-a71e-97f8b1749e6d" xlink:to="loc_us-gaap_StatementTable_019d2bfc-44f2-7e66-8165-4bfe4121c8cd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-44f2-756e-912e-d48699c182d9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019d2bfc-44f2-7e66-8165-4bfe4121c8cd" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-44f2-756e-912e-d48699c182d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019d2bfc-44f2-756e-912e-d48699c182d9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-44f2-756e-912e-d48699c182d9" xlink:to="loc_us-gaap_RelatedPartyDomain_019d2bfc-44f2-756e-912e-d48699c182d9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019d2bfc-44f2-7f88-86fb-628ececa23bd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-44f2-756e-912e-d48699c182d9" xlink:to="loc_us-gaap_RelatedPartyDomain_019d2bfc-44f2-7f88-86fb-628ececa23bd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019d2bfc-44f2-7d7d-9e36-bf172ab3c1d2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019d2bfc-44f2-7f88-86fb-628ececa23bd" xlink:to="loc_us-gaap_RelatedPartyMember_019d2bfc-44f2-7d7d-9e36-bf172ab3c1d2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonrelatedPartyMember_019d2bfc-44f2-7827-8cf4-478fa749ae70" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonrelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019d2bfc-44f2-7f88-86fb-628ececa23bd" xlink:to="loc_us-gaap_NonrelatedPartyMember_019d2bfc-44f2-7827-8cf4-478fa749ae70" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_019d2bfc-44f2-7eb8-bc38-6cc92a94a243" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-72f4-a71e-97f8b1749e6d" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_019d2bfc-44f2-7eb8-bc38-6cc92a94a243" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019d2bfc-44f2-7777-80b2-1510ff9dbaac" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_019d2bfc-44f2-7eb8-bc38-6cc92a94a243" xlink:to="loc_us-gaap_ProfitLoss_019d2bfc-44f2-7777-80b2-1510ff9dbaac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019d2bfc-44f2-7a4e-8896-458418d67d18" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_019d2bfc-44f2-7eb8-bc38-6cc92a94a243" xlink:to="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019d2bfc-44f2-7a4e-8896-458418d67d18" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationAndAmortization_019d2bfc-44f2-7f0e-9c0c-9c7a1a3fc609" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019d2bfc-44f2-7a4e-8896-458418d67d18" xlink:to="loc_us-gaap_DepreciationAndAmortization_019d2bfc-44f2-7f0e-9c0c-9c7a1a3fc609" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_019d2bfc-44f2-72af-90f8-cce45f361cfa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019d2bfc-44f2-7a4e-8896-458418d67d18" xlink:to="loc_us-gaap_ShareBasedCompensation_019d2bfc-44f2-72af-90f8-cce45f361cfa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCosts_019d2bfc-44f2-76b6-9fb2-52ce4d73492e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfFinancingCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019d2bfc-44f2-7a4e-8896-458418d67d18" xlink:to="loc_us-gaap_AmortizationOfFinancingCosts_019d2bfc-44f2-76b6-9fb2-52ce4d73492e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss_019d2bfc-44f2-7e1b-802d-f6bb42181a80" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019d2bfc-44f2-7a4e-8896-458418d67d18" xlink:to="loc_us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss_019d2bfc-44f2-7e1b-802d-f6bb42181a80" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LifeSettlementContractsFairValueMethodUnrealizedGainLoss_019d2bfc-44f2-7d62-9e25-8cb442569ddd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LifeSettlementContractsFairValueMethodUnrealizedGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019d2bfc-44f2-7a4e-8896-458418d67d18" xlink:to="loc_us-gaap_LifeSettlementContractsFairValueMethodUnrealizedGainLoss_019d2bfc-44f2-7d62-9e25-8cb442569ddd" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_019d2bfc-44f2-7417-9f55-08ebaa181867" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019d2bfc-44f2-7a4e-8896-458418d67d18" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_019d2bfc-44f2-7417-9f55-08ebaa181867" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAdjustmentOfWarrants_019d2bfc-44f2-7988-a094-70ee945b9d88" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAdjustmentOfWarrants"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019d2bfc-44f2-7a4e-8896-458418d67d18" xlink:to="loc_us-gaap_FairValueAdjustmentOfWarrants_019d2bfc-44f2-7988-a094-70ee945b9d88" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxesAndTaxCredits_019d2bfc-44f2-7d9a-8084-e22f7f7c303a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxesAndTaxCredits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019d2bfc-44f2-7a4e-8896-458418d67d18" xlink:to="loc_us-gaap_DeferredIncomeTaxesAndTaxCredits_019d2bfc-44f2-7d9a-8084-e22f7f7c303a" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeOperatingPaidInKind_019d2bfc-44f2-7546-8483-3f5687b7c655" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeOperatingPaidInKind"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019d2bfc-44f2-7a4e-8896-458418d67d18" xlink:to="loc_us-gaap_InterestIncomeOperatingPaidInKind_019d2bfc-44f2-7546-8483-3f5687b7c655" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaidInKindInterest_019d2bfc-44f2-710e-9495-1b9f0f25c331" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaidInKindInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019d2bfc-44f2-7a4e-8896-458418d67d18" xlink:to="loc_us-gaap_PaidInKindInterest_019d2bfc-44f2-710e-9495-1b9f0f25c331" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_OperatingLeaseRightOfUseAssetNoncashIncomeExpense_019d2bfc-44f2-7c83-8fc3-38e199c9ec13" xlink:href="abx-20260331.xsd#abx_OperatingLeaseRightOfUseAssetNoncashIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019d2bfc-44f2-7a4e-8896-458418d67d18" xlink:to="loc_abx_OperatingLeaseRightOfUseAssetNoncashIncomeExpense_019d2bfc-44f2-7c83-8fc3-38e199c9ec13" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019d2bfc-44f2-7b07-af76-beb9fbd2ce19" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019d2bfc-44f2-7a4e-8896-458418d67d18" xlink:to="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019d2bfc-44f2-7b07-af76-beb9fbd2ce19" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_019d2bfc-44f2-7a41-87cf-f941d5c485c7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019d2bfc-44f2-7b07-af76-beb9fbd2ce19" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_019d2bfc-44f2-7a41-87cf-f941d5c485c7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivableRelatedParties_019d2bfc-44f2-7a92-9144-a3f71bc45d63" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsReceivableRelatedParties"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019d2bfc-44f2-7b07-af76-beb9fbd2ce19" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsReceivableRelatedParties_019d2bfc-44f2-7a92-9144-a3f71bc45d63" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_IncreaseDecreaseInManagementAndPerformanceFeeReceivable_019d2bfc-44f2-73aa-81eb-98e34a8b7a16" xlink:href="abx-20260331.xsd#abx_IncreaseDecreaseInManagementAndPerformanceFeeReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019d2bfc-44f2-7b07-af76-beb9fbd2ce19" xlink:to="loc_abx_IncreaseDecreaseInManagementAndPerformanceFeeReceivable_019d2bfc-44f2-73aa-81eb-98e34a8b7a16" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_019d2bfc-44f2-7d0c-b0bf-36161b1398f0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019d2bfc-44f2-7b07-af76-beb9fbd2ce19" xlink:to="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_019d2bfc-44f2-7d0c-b0bf-36161b1398f0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_IncreaseDecreaseInOtherInvestments_019df935-591b-71b9-9fe4-adbeafa53322" xlink:href="abx-20260331.xsd#abx_IncreaseDecreaseInOtherInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019d2bfc-44f2-7b07-af76-beb9fbd2ce19" xlink:to="loc_abx_IncreaseDecreaseInOtherInvestments_019df935-591b-71b9-9fe4-adbeafa53322" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets_019d2bfc-44f2-7ffc-b9c1-b0d656c1c63c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019d2bfc-44f2-7b07-af76-beb9fbd2ce19" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets_019d2bfc-44f2-7ffc-b9c1-b0d656c1c63c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedLiabilities_019d2bfc-44f2-7c79-b5d5-aa353131eebe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019d2bfc-44f2-7b07-af76-beb9fbd2ce19" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedLiabilities_019d2bfc-44f2-7c79-b5d5-aa353131eebe" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_IncreaseDecreaseInAccruedTransactionCosts_019d2bfc-44f2-7ef1-b162-ca7574642ce1" xlink:href="abx-20260331.xsd#abx_IncreaseDecreaseInAccruedTransactionCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019d2bfc-44f2-7b07-af76-beb9fbd2ce19" xlink:to="loc_abx_IncreaseDecreaseInAccruedTransactionCosts_019d2bfc-44f2-7ef1-b162-ca7574642ce1" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_019d2bfc-44f2-772b-966a-863e23a7aed5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInContractWithCustomerLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019d2bfc-44f2-7b07-af76-beb9fbd2ce19" xlink:to="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_019d2bfc-44f2-772b-966a-863e23a7aed5" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherCurrentLiabilities_019d2bfc-44f2-79df-8510-2c280a438934" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOtherCurrentLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019d2bfc-44f2-7b07-af76-beb9fbd2ce19" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherCurrentLiabilities_019d2bfc-44f2-79df-8510-2c280a438934" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_019ddecf-03b7-7022-9a5f-79e56ad61efa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019d2bfc-44f2-7b07-af76-beb9fbd2ce19" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_019ddecf-03b7-7022-9a5f-79e56ad61efa" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInIncomeTaxesReceivable_019d2bfc-44f2-7ff3-8d67-3e530c70cfd7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInIncomeTaxesReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019d2bfc-44f2-7b07-af76-beb9fbd2ce19" xlink:to="loc_us-gaap_IncreaseDecreaseInIncomeTaxesReceivable_019d2bfc-44f2-7ff3-8d67-3e530c70cfd7" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_IncreaseDecreaseInRetrocessionFeesPayable_019d2bfc-44f2-73a7-bea6-975dad7b83a9" xlink:href="abx-20260331.xsd#abx_IncreaseDecreaseInRetrocessionFeesPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019d2bfc-44f2-7b07-af76-beb9fbd2ce19" xlink:to="loc_abx_IncreaseDecreaseInRetrocessionFeesPayable_019d2bfc-44f2-73a7-bea6-975dad7b83a9" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseDueFromAffiliates_019dd45b-560e-76bd-b296-c7cef05a2acc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseDueFromAffiliates"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019d2bfc-44f2-7b07-af76-beb9fbd2ce19" xlink:to="loc_us-gaap_IncreaseDecreaseDueFromAffiliates_019dd45b-560e-76bd-b296-c7cef05a2acc" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSettlementContractPurchasedFairValueMethod_019d2bfc-44f2-71de-8a59-c4596ad35161" xlink:href="abx-20260331.xsd#abx_LifeSettlementContractPurchasedFairValueMethod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019d2bfc-44f2-7b07-af76-beb9fbd2ce19" xlink:to="loc_abx_LifeSettlementContractPurchasedFairValueMethod_019d2bfc-44f2-71de-8a59-c4596ad35161" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSettlementContractPurchasedInvestmentMethod_019d2bfc-44f2-7748-ac3b-45fb83119e5c" xlink:href="abx-20260331.xsd#abx_LifeSettlementContractPurchasedInvestmentMethod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019d2bfc-44f2-7b07-af76-beb9fbd2ce19" xlink:to="loc_abx_LifeSettlementContractPurchasedInvestmentMethod_019d2bfc-44f2-7748-ac3b-45fb83119e5c" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019d2bfc-44f2-7184-b2c5-12efd2d3a821" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_019d2bfc-44f2-7eb8-bc38-6cc92a94a243" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019d2bfc-44f2-7184-b2c5-12efd2d3a821" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019d2bfc-44f2-77ca-9e4f-39bed2b3ae44" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-72f4-a71e-97f8b1749e6d" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019d2bfc-44f2-77ca-9e4f-39bed2b3ae44" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_019d2bfc-44f2-7cba-85e8-93a0e5e23236" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019d2bfc-44f2-77ca-9e4f-39bed2b3ae44" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_019d2bfc-44f2-7cba-85e8-93a0e5e23236" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireIntangibleAssets_019d2bfc-44f2-7498-b646-01945f2a3844" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019d2bfc-44f2-77ca-9e4f-39bed2b3ae44" xlink:to="loc_us-gaap_PaymentsToAcquireIntangibleAssets_019d2bfc-44f2-7498-b646-01945f2a3844" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireOtherInvestments_019d2bfc-44f2-724c-9330-9754697ece70" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireOtherInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019d2bfc-44f2-77ca-9e4f-39bed2b3ae44" xlink:to="loc_us-gaap_PaymentsToAcquireOtherInvestments_019d2bfc-44f2-724c-9330-9754697ece70" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_019d2bfc-44f2-7692-8f69-ceee75124d87" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019d2bfc-44f2-77ca-9e4f-39bed2b3ae44" xlink:to="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_019d2bfc-44f2-7692-8f69-ceee75124d87" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d2bfc-44f2-7d87-bb6b-afcef82ba5e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019d2bfc-44f2-77ca-9e4f-39bed2b3ae44" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d2bfc-44f2-7d87-bb6b-afcef82ba5e7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019d2bfc-44f2-7cff-9337-fbc58b652827" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-72f4-a71e-97f8b1749e6d" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019d2bfc-44f2-7cff-9337-fbc58b652827" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_019d2bfc-44f2-7c36-a789-62358be1e383" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfLongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019d2bfc-44f2-7cff-9337-fbc58b652827" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_019d2bfc-44f2-7c36-a789-62358be1e383" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfFinancingCosts_019d2bfc-44f2-75f3-a56a-47b40e21aab4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfFinancingCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019d2bfc-44f2-7cff-9337-fbc58b652827" xlink:to="loc_us-gaap_PaymentsOfFinancingCosts_019d2bfc-44f2-75f3-a56a-47b40e21aab4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfLongTermDebt_019d2bfc-44f2-7ad1-ae9f-0ab74d765c67" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RepaymentsOfLongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019d2bfc-44f2-7cff-9337-fbc58b652827" xlink:to="loc_us-gaap_RepaymentsOfLongTermDebt_019d2bfc-44f2-7ad1-ae9f-0ab74d765c67" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfStockIssuanceCosts_019d2bfc-44f2-7643-8699-1da5449a5abd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfStockIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019d2bfc-44f2-7cff-9337-fbc58b652827" xlink:to="loc_us-gaap_PaymentsOfStockIssuanceCosts_019d2bfc-44f2-7643-8699-1da5449a5abd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_019d2bfc-44f2-7219-99cf-9302dcbc9b1f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019d2bfc-44f2-7cff-9337-fbc58b652827" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_019d2bfc-44f2-7219-99cf-9302dcbc9b1f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock_019ddecf-a96a-7d34-91f8-e2da7e7961ce" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019d2bfc-44f2-7cff-9337-fbc58b652827" xlink:to="loc_us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock_019ddecf-a96a-7d34-91f8-e2da7e7961ce" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019d2bfc-44f2-700c-9624-8ef4dca6ad7a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019d2bfc-44f2-7cff-9337-fbc58b652827" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019d2bfc-44f2-700c-9624-8ef4dca6ad7a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019d2bfc-44f2-743d-b9dc-61002624c68d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-72f4-a71e-97f8b1749e6d" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019d2bfc-44f2-743d-b9dc-61002624c68d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019d2bfc-44f2-7550-8e14-7347ae16db4f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-72f4-a71e-97f8b1749e6d" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019d2bfc-44f2-7550-8e14-7347ae16db4f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019d2bfc-44f2-7243-84e5-b17d761a219c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncashInvestingAndFinancingItemsAbstract_019d2bfc-44f2-7f06-9772-c89b0d50e9f8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoncashInvestingAndFinancingItemsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-72f4-a71e-97f8b1749e6d" xlink:to="loc_us-gaap_NoncashInvestingAndFinancingItemsAbstract_019d2bfc-44f2-7f06-9772-c89b0d50e9f8" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_NoncashOtherInvestments_019d2bfc-44f2-7023-944a-b4f83412ebce" xlink:href="abx-20260331.xsd#abx_NoncashOtherInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoncashInvestingAndFinancingItemsAbstract_019d2bfc-44f2-7f06-9772-c89b0d50e9f8" xlink:to="loc_abx_NoncashOtherInvestments_019d2bfc-44f2-7023-944a-b4f83412ebce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssued1_019d2bfc-44f2-717a-8823-c716572afcc9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssued1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoncashInvestingAndFinancingItemsAbstract_019d2bfc-44f2-7f06-9772-c89b0d50e9f8" xlink:to="loc_us-gaap_StockIssued1_019d2bfc-44f2-717a-8823-c716572afcc9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplementalCashFlowInformationAbstract_019d2bfc-44f2-74ad-b193-c84b91b03acc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SupplementalCashFlowInformationAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2bfc-44f2-72f4-a71e-97f8b1749e6d" xlink:to="loc_us-gaap_SupplementalCashFlowInformationAbstract_019d2bfc-44f2-74ad-b193-c84b91b03acc" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestPaidNet_019d2bfc-44f2-7331-9aac-9fddfc120f75" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestPaidNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract_019d2bfc-44f2-74ad-b193-c84b91b03acc" xlink:to="loc_us-gaap_InterestPaidNet_019d2bfc-44f2-7331-9aac-9fddfc120f75" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnInvestments_019df93c-cd9f-7265-9c50-19e9765ca1b7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrealizedGainLossOnInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract_019d2bfc-44f2-74ad-b193-c84b91b03acc" xlink:to="loc_us-gaap_UnrealizedGainLossOnInvestments_019df93c-cd9f-7265-9c50-19e9765ca1b7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueImpairmentLossAnnualAmount_019df948-cecb-75d3-bbe2-72abaaf1f736" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueImpairmentLossAnnualAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract_019d2bfc-44f2-74ad-b193-c84b91b03acc" xlink:to="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueImpairmentLossAnnualAmount_019df948-cecb-75d3-bbe2-72abaaf1f736" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskLineItems_019d2bfc-45ae-713f-8d3b-cc713e3fbe09" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTable_019d2bfc-45ae-7446-b3f7-1c2ed5e8e8a5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_019d2bfc-45ae-713f-8d3b-cc713e3fbe09" xlink:to="loc_us-gaap_ConcentrationRiskTable_019d2bfc-45ae-7446-b3f7-1c2ed5e8e8a5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_019d2bfc-45ae-7e2f-8880-8c12d80d0922" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_019d2bfc-45ae-7446-b3f7-1c2ed5e8e8a5" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_019d2bfc-45ae-7e2f-8880-8c12d80d0922" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019d2bfc-45ae-7e2f-8880-8c12d80d0922_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019d2bfc-45ae-7e2f-8880-8c12d80d0922" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019d2bfc-45ae-7e2f-8880-8c12d80d0922_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019d2bfc-45ae-7d40-b2ad-a3dfa3a61ee7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019d2bfc-45ae-7e2f-8880-8c12d80d0922" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019d2bfc-45ae-7d40-b2ad-a3dfa3a61ee7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember_019d2bfc-45ae-7981-8c58-6880c4a28374" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_019d2bfc-45ae-7d40-b2ad-a3dfa3a61ee7" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember_019d2bfc-45ae-7981-8c58-6880c4a28374" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019d2bfc-45ae-7633-924f-2957b77a7497" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_019d2bfc-45ae-7446-b3f7-1c2ed5e8e8a5" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019d2bfc-45ae-7633-924f-2957b77a7497" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019d2bfc-45ae-7633-924f-2957b77a7497_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019d2bfc-45ae-7633-924f-2957b77a7497" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019d2bfc-45ae-7633-924f-2957b77a7497_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019d2bfc-45ae-7eb6-9596-362346875259" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019d2bfc-45ae-7633-924f-2957b77a7497" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019d2bfc-45ae-7eb6-9596-362346875259" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesRevenueNetMember_019dd468-cf3c-71e1-8e27-0042ca84b21c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SalesRevenueNetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019d2bfc-45ae-7eb6-9596-362346875259" xlink:to="loc_us-gaap_SalesRevenueNetMember_019dd468-cf3c-71e1-8e27-0042ca84b21c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_019d2bfc-45ae-7443-ada5-ee2aac8d743e" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_019d2bfc-45ae-7446-b3f7-1c2ed5e8e8a5" xlink:to="loc_srt_MajorCustomersAxis_019d2bfc-45ae-7443-ada5-ee2aac8d743e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_019d2bfc-45ae-7443-ada5-ee2aac8d743e_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_019d2bfc-45ae-7443-ada5-ee2aac8d743e" xlink:to="loc_srt_NameOfMajorCustomerDomain_019d2bfc-45ae-7443-ada5-ee2aac8d743e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_019d2bfc-45ae-7fd2-933d-036860e73c2b" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_019d2bfc-45ae-7443-ada5-ee2aac8d743e" xlink:to="loc_srt_NameOfMajorCustomerDomain_019d2bfc-45ae-7fd2-933d-036860e73c2b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_Customer1Member_019d2bfc-45ae-7d04-9b3d-a652adc3833c" xlink:href="abx-20260331.xsd#abx_Customer1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019d2bfc-45ae-7fd2-933d-036860e73c2b" xlink:to="loc_abx_Customer1Member_019d2bfc-45ae-7d04-9b3d-a652adc3833c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_Customer2Member_019d2bfc-45ae-79d4-8799-9d5adcca1b12" xlink:href="abx-20260331.xsd#abx_Customer2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019d2bfc-45ae-7fd2-933d-036860e73c2b" xlink:to="loc_abx_Customer2Member_019d2bfc-45ae-79d4-8799-9d5adcca1b12" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_Customer3Member_019d2bfc-45ae-7c13-bcf3-dcd580e09054" xlink:href="abx-20260331.xsd#abx_Customer3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019d2bfc-45ae-7fd2-933d-036860e73c2b" xlink:to="loc_abx_Customer3Member_019d2bfc-45ae-7c13-bcf3-dcd580e09054" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019d2bfc-45ae-7651-b0d0-6cd2afdf2003" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_019d2bfc-45ae-7446-b3f7-1c2ed5e8e8a5" xlink:to="loc_srt_ProductOrServiceAxis_019d2bfc-45ae-7651-b0d0-6cd2afdf2003" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019d2bfc-45ae-7651-b0d0-6cd2afdf2003_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019d2bfc-45ae-7651-b0d0-6cd2afdf2003" xlink:to="loc_srt_ProductsAndServicesDomain_019d2bfc-45ae-7651-b0d0-6cd2afdf2003_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019d2bfc-45ae-7f90-9263-bb835cb5d807" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019d2bfc-45ae-7651-b0d0-6cd2afdf2003" xlink:to="loc_srt_ProductsAndServicesDomain_019d2bfc-45ae-7f90-9263-bb835cb5d807" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSolutionsMember_019d2bfc-45ae-7c4a-b9a4-29cb52c85b1b" xlink:href="abx-20260331.xsd#abx_LifeSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019d2bfc-45ae-7f90-9263-bb835cb5d807" xlink:to="loc_abx_LifeSolutionsMember_019d2bfc-45ae-7c4a-b9a4-29cb52c85b1b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_019d2bfc-45ae-70e5-afb5-f1554087e7f1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_019d2bfc-45ae-713f-8d3b-cc713e3fbe09" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_019d2bfc-45ae-70e5-afb5-f1554087e7f1" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/BUSINESSCOMBINATIONSNarrativeDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#BUSINESSCOMBINATIONSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/BUSINESSCOMBINATIONSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019dd472-01f3-7e82-adc8-1131c7c9968c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019d2bfc-45ae-7913-bfc7-5dbdbe068654" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019dd472-01f3-7e82-adc8-1131c7c9968c" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019d2bfc-45ae-7913-bfc7-5dbdbe068654" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipAxis_019dd472-01f3-7d25-856b-fe28c7316a64" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_OwnershipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019d2bfc-45ae-7913-bfc7-5dbdbe068654" xlink:to="loc_srt_OwnershipAxis_019dd472-01f3-7d25-856b-fe28c7316a64" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_019dd472-01f3-7d25-856b-fe28c7316a64_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_OwnershipAxis_019dd472-01f3-7d25-856b-fe28c7316a64" xlink:to="loc_srt_OwnershipDomain_019dd472-01f3-7d25-856b-fe28c7316a64_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_019dd472-01f3-7922-a67b-4146dc2cfbfa" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_OwnershipAxis_019dd472-01f3-7d25-856b-fe28c7316a64" xlink:to="loc_srt_OwnershipDomain_019dd472-01f3-7922-a67b-4146dc2cfbfa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_NationalInsuranceBrokerageMember_019dd472-01f3-76d2-ae87-fc3042f7e8d2" xlink:href="abx-20260331.xsd#abx_NationalInsuranceBrokerageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_019dd472-01f3-7922-a67b-4146dc2cfbfa" xlink:to="loc_abx_NationalInsuranceBrokerageMember_019dd472-01f3-76d2-ae87-fc3042f7e8d2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019dd472-01f3-7460-a2ec-4f2836a91105" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019d2bfc-45ae-7913-bfc7-5dbdbe068654" xlink:to="loc_dei_LegalEntityAxis_019dd472-01f3-7460-a2ec-4f2836a91105" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019dd472-01f3-7460-a2ec-4f2836a91105_default" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019dd472-01f3-7460-a2ec-4f2836a91105" xlink:to="loc_dei_EntityDomain_019dd472-01f3-7460-a2ec-4f2836a91105_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019dd472-01f3-7c67-be8b-6d35bbd29739" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019dd472-01f3-7460-a2ec-4f2836a91105" xlink:to="loc_dei_EntityDomain_019dd472-01f3-7c67-be8b-6d35bbd29739" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_JayJacksonMember_019dd472-01f3-745f-adc6-695be7e31e4c" xlink:href="abx-20260331.xsd#abx_JayJacksonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019dd472-01f3-7c67-be8b-6d35bbd29739" xlink:to="loc_abx_JayJacksonMember_019dd472-01f3-745f-adc6-695be7e31e4c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_KMGGroupHoldingsLLCMember_019dd472-01f3-7d16-8645-5629baa0aed1" xlink:href="abx-20260331.xsd#abx_KMGGroupHoldingsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019dd472-01f3-7c67-be8b-6d35bbd29739" xlink:to="loc_abx_KMGGroupHoldingsLLCMember_019dd472-01f3-7d16-8645-5629baa0aed1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019dd472-01f3-74e9-8011-c653c2f8256d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019d2bfc-45ae-7913-bfc7-5dbdbe068654" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019dd472-01f3-74e9-8011-c653c2f8256d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019dd472-01f3-74e9-8011-c653c2f8256d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019dd472-01f3-74e9-8011-c653c2f8256d" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019dd472-01f3-74e9-8011-c653c2f8256d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019dd472-01f3-7927-abaa-c180a08b0c76" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019dd472-01f3-74e9-8011-c653c2f8256d" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019dd472-01f3-7927-abaa-c180a08b0c76" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_NationalInsuranceBrokerageMember_019dd472-01f3-763b-89f6-f3904ce09906" xlink:href="abx-20260331.xsd#abx_NationalInsuranceBrokerageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019dd472-01f3-7927-abaa-c180a08b0c76" xlink:to="loc_abx_NationalInsuranceBrokerageMember_019dd472-01f3-763b-89f6-f3904ce09906" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_AccuQuoteMember_019dd472-2c55-7e6f-bfc6-4522d8c52b6c" xlink:href="abx-20260331.xsd#abx_AccuQuoteMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019dd472-01f3-7927-abaa-c180a08b0c76" xlink:to="loc_abx_AccuQuoteMember_019dd472-2c55-7e6f-bfc6-4522d8c52b6c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPManagingMemberOrGeneralPartnerOwnershipInterest_019dd472-01f3-7871-af67-b58762ff871a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPManagingMemberOrGeneralPartnerOwnershipInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019dd472-01f3-7e82-adc8-1131c7c9968c" xlink:to="loc_us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPManagingMemberOrGeneralPartnerOwnershipInterest_019dd472-01f3-7871-af67-b58762ff871a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_019dd472-01f3-72f2-ac46-a94558999b83" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019dd472-01f3-7e82-adc8-1131c7c9968c" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_019dd472-01f3-72f2-ac46-a94558999b83" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_019dd472-01f3-7ca0-96ad-66665c7ad42c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019dd472-01f3-7e82-adc8-1131c7c9968c" xlink:to="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_019dd472-01f3-7ca0-96ad-66665c7ad42c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_019dd472-2c55-7fa4-9f79-1bd15616d462" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019dd472-01f3-7e82-adc8-1131c7c9968c" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_019dd472-2c55-7fa4-9f79-1bd15616d462" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAcquiredFromAcquisition_019dd472-2c55-7819-b508-0f13129fb7d4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAcquiredFromAcquisition"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019dd472-01f3-7e82-adc8-1131c7c9968c" xlink:to="loc_us-gaap_CashAcquiredFromAcquisition_019dd472-2c55-7819-b508-0f13129fb7d4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_019dd472-2c55-7fa9-bde3-ea908cb88da7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019dd472-01f3-7e82-adc8-1131c7c9968c" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_019dd472-2c55-7fa9-bde3-ea908cb88da7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_NoteReceivableGuaranteePercentageOfBorrowerAssets_019dd472-2c55-7a93-a4e6-adfa287fab4d" xlink:href="abx-20260331.xsd#abx_NoteReceivableGuaranteePercentageOfBorrowerAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019dd472-01f3-7e82-adc8-1131c7c9968c" xlink:to="loc_abx_NoteReceivableGuaranteePercentageOfBorrowerAssets_019dd472-2c55-7a93-a4e6-adfa287fab4d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_BusinessCombinationNoteReceivableTermPriorToAcquisitionDate_019dd472-2c55-7a3c-9958-5b1a95dbb64a" xlink:href="abx-20260331.xsd#abx_BusinessCombinationNoteReceivableTermPriorToAcquisitionDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019dd472-01f3-7e82-adc8-1131c7c9968c" xlink:to="loc_abx_BusinessCombinationNoteReceivableTermPriorToAcquisitionDate_019dd472-2c55-7a3c-9958-5b1a95dbb64a" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/BUSINESSCOMBINATIONSPurchasePriceAllocationDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#BUSINESSCOMBINATIONSPurchasePriceAllocationDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/BUSINESSCOMBINATIONSPurchasePriceAllocationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019d2bfc-45ae-7b92-8fe7-c603cbb9b2ea" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019d2bfc-45ae-7975-8482-2e744a8bf217" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019d2bfc-45ae-7b92-8fe7-c603cbb9b2ea" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019d2bfc-45ae-7975-8482-2e744a8bf217" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019d2bfc-45ae-735a-a869-410821a4badd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019d2bfc-45ae-7975-8482-2e744a8bf217" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019d2bfc-45ae-735a-a869-410821a4badd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019d2bfc-45ae-735a-a869-410821a4badd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019d2bfc-45ae-735a-a869-410821a4badd" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019d2bfc-45ae-735a-a869-410821a4badd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019d2bfc-45ae-7f6e-8e65-a78f1f50e7f8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019d2bfc-45ae-735a-a869-410821a4badd" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019d2bfc-45ae-7f6e-8e65-a78f1f50e7f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_NationalInsuranceBrokerageMember_019d2bfc-45ae-73fe-872f-0ea19aecae3d" xlink:href="abx-20260331.xsd#abx_NationalInsuranceBrokerageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019d2bfc-45ae-7f6e-8e65-a78f1f50e7f8" xlink:to="loc_abx_NationalInsuranceBrokerageMember_019d2bfc-45ae-73fe-872f-0ea19aecae3d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_AccuQuoteMember_019d2bfc-45ae-74ba-82ff-9934c08b9720" xlink:href="abx-20260331.xsd#abx_AccuQuoteMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019d2bfc-45ae-7f6e-8e65-a78f1f50e7f8" xlink:to="loc_abx_AccuQuoteMember_019d2bfc-45ae-74ba-82ff-9934c08b9720" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_019d2bfc-45ae-7837-ac47-469b1734d1bf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019d2bfc-45ae-7b92-8fe7-c603cbb9b2ea" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_019d2bfc-45ae-7837-ac47-469b1734d1bf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_019d2bfc-45ae-759a-8059-a9f5b512bdee" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019d2bfc-45ae-7b92-8fe7-c603cbb9b2ea" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_019d2bfc-45ae-759a-8059-a9f5b512bdee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets_019d2bfc-45ae-76f6-b666-fccb09e2f7cb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019d2bfc-45ae-7b92-8fe7-c603cbb9b2ea" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets_019d2bfc-45ae-76f6-b666-fccb09e2f7cb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenses_019d2bfc-45ae-725c-a847-4cd444604d59" xlink:href="abx-20260331.xsd#abx_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019d2bfc-45ae-7b92-8fe7-c603cbb9b2ea" xlink:to="loc_abx_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenses_019d2bfc-45ae-725c-a847-4cd444604d59" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesOther_019d2bfc-45ae-7aa9-852b-1b97ac4cfcef" xlink:href="abx-20260331.xsd#abx_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019d2bfc-45ae-7b92-8fe7-c603cbb9b2ea" xlink:to="loc_abx_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesOther_019d2bfc-45ae-7aa9-852b-1b97ac4cfcef" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_019d2bfc-45ae-7601-94af-b257b9a6e677" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019d2bfc-45ae-7b92-8fe7-c603cbb9b2ea" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_019d2bfc-45ae-7601-94af-b257b9a6e677" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019d2bfc-45ae-7e9a-bd93-b39a2c60fd7c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019d2bfc-45ae-7b92-8fe7-c603cbb9b2ea" xlink:to="loc_us-gaap_Goodwill_019d2bfc-45ae-7e9a-bd93-b39a2c60fd7c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_019d2bfc-45ae-770d-88c5-2ea2a538475a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019d2bfc-45ae-7b92-8fe7-c603cbb9b2ea" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_019d2bfc-45ae-770d-88c5-2ea2a538475a" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/BUSINESSCOMBINATIONSIntangibleAssetsAcquiredDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#BUSINESSCOMBINATIONSIntangibleAssetsAcquiredDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/BUSINESSCOMBINATIONSIntangibleAssetsAcquiredDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019d2bfc-45ae-77c0-97d5-ab0a37bdd4e0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019d2bfc-45ae-74fc-b16f-8dc608253be4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019d2bfc-45ae-77c0-97d5-ab0a37bdd4e0" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019d2bfc-45ae-74fc-b16f-8dc608253be4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019d2bfc-45ae-7757-981a-65a01f68901e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019d2bfc-45ae-74fc-b16f-8dc608253be4" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019d2bfc-45ae-7757-981a-65a01f68901e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019d2bfc-45ae-7757-981a-65a01f68901e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019d2bfc-45ae-7757-981a-65a01f68901e" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019d2bfc-45ae-7757-981a-65a01f68901e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019d2bfc-45ae-7f32-b3ec-30d665ba7509" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019d2bfc-45ae-7757-981a-65a01f68901e" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019d2bfc-45ae-7f32-b3ec-30d665ba7509" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_NationalInsuranceBrokerageMember_019d2bfc-45ae-76c8-bb59-001f62ed2bbb" xlink:href="abx-20260331.xsd#abx_NationalInsuranceBrokerageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019d2bfc-45ae-7f32-b3ec-30d665ba7509" xlink:to="loc_abx_NationalInsuranceBrokerageMember_019d2bfc-45ae-76c8-bb59-001f62ed2bbb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_AccuQuoteMember_019d2bfc-45ae-791f-ae97-74a2586faa05" xlink:href="abx-20260331.xsd#abx_AccuQuoteMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019d2bfc-45ae-7f32-b3ec-30d665ba7509" xlink:to="loc_abx_AccuQuoteMember_019d2bfc-45ae-791f-ae97-74a2586faa05" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019d2bfc-45ae-7cba-b218-0cce61db7cd9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019d2bfc-45ae-74fc-b16f-8dc608253be4" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019d2bfc-45ae-7cba-b218-0cce61db7cd9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-7cba-b218-0cce61db7cd9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019d2bfc-45ae-7cba-b218-0cce61db7cd9" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-7cba-b218-0cce61db7cd9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-73a5-988b-084ea79eae33" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019d2bfc-45ae-7cba-b218-0cce61db7cd9" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-73a5-988b-084ea79eae33" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_019d2bfc-45ae-7ea2-8df2-514582afbfb9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-73a5-988b-084ea79eae33" xlink:to="loc_us-gaap_CustomerRelationshipsMember_019d2bfc-45ae-7ea2-8df2-514582afbfb9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_019d2bfc-45ae-7ab8-8769-8f3c68a5383f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-73a5-988b-084ea79eae33" xlink:to="loc_us-gaap_TradeNamesMember_019d2bfc-45ae-7ab8-8769-8f3c68a5383f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_019d2bfc-45ae-7120-abfc-184ef53506e5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019d2bfc-45ae-77c0-97d5-ab0a37bdd4e0" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_019d2bfc-45ae-7120-abfc-184ef53506e5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_019d2bfc-45ae-77cd-bf2e-fa4968a894b3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019d2bfc-45ae-77c0-97d5-ab0a37bdd4e0" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_019d2bfc-45ae-77cd-bf2e-fa4968a894b3" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/REVENUESDisaggregatedRevenueDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#REVENUESDisaggregatedRevenueDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/REVENUESDisaggregatedRevenueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019d2bfc-45ae-76b5-8a34-6c5e4e914f4b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_019d2bfc-45ae-78c9-913b-944dfc61f8ff" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019d2bfc-45ae-76b5-8a34-6c5e4e914f4b" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019d2bfc-45ae-78c9-913b-944dfc61f8ff" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019d2bfc-45ae-7597-80c7-f96de0c9d623" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019d2bfc-45ae-78c9-913b-944dfc61f8ff" xlink:to="loc_srt_ProductOrServiceAxis_019d2bfc-45ae-7597-80c7-f96de0c9d623" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019d2bfc-45ae-7597-80c7-f96de0c9d623_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019d2bfc-45ae-7597-80c7-f96de0c9d623" xlink:to="loc_srt_ProductsAndServicesDomain_019d2bfc-45ae-7597-80c7-f96de0c9d623_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019d2bfc-45ae-77c3-b1f3-deef29b719af" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019d2bfc-45ae-7597-80c7-f96de0c9d623" xlink:to="loc_srt_ProductsAndServicesDomain_019d2bfc-45ae-77c3-b1f3-deef29b719af" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetManagement1Member_019d2bfc-45ae-722c-8b57-aa41affe9c1e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetManagement1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019d2bfc-45ae-77c3-b1f3-deef29b719af" xlink:to="loc_us-gaap_AssetManagement1Member_019d2bfc-45ae-722c-8b57-aa41affe9c1e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_AssetManagementFeeMember_019d2bfc-45ae-78a1-aa3b-9130d1f365cb" xlink:href="abx-20260331.xsd#abx_AssetManagementFeeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetManagement1Member_019d2bfc-45ae-722c-8b57-aa41affe9c1e" xlink:to="loc_abx_AssetManagementFeeMember_019d2bfc-45ae-78a1-aa3b-9130d1f365cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_PortfolioServicesMember_019d2bfc-45ae-7791-8970-acefb74c8eea" xlink:href="abx-20260331.xsd#abx_PortfolioServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetManagement1Member_019d2bfc-45ae-722c-8b57-aa41affe9c1e" xlink:to="loc_abx_PortfolioServicesMember_019d2bfc-45ae-7791-8970-acefb74c8eea" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSolutionsMember_019d2bfc-45ae-7343-9a2d-dd4a8692464b" xlink:href="abx-20260331.xsd#abx_LifeSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019d2bfc-45ae-77c3-b1f3-deef29b719af" xlink:to="loc_abx_LifeSolutionsMember_019d2bfc-45ae-7343-9a2d-dd4a8692464b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_OriginationMember_019d2bfc-45ae-7068-a10c-1cabe83be2ed" xlink:href="abx-20260331.xsd#abx_OriginationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_LifeSolutionsMember_019d2bfc-45ae-7343-9a2d-dd4a8692464b" xlink:to="loc_abx_OriginationMember_019d2bfc-45ae-7068-a10c-1cabe83be2ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TechnologyServiceMember_019d2bfc-45ae-7646-ab43-8fc6bb907790" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TechnologyServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019d2bfc-45ae-77c3-b1f3-deef29b719af" xlink:to="loc_us-gaap_TechnologyServiceMember_019d2bfc-45ae-7646-ab43-8fc6bb907790" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-45ae-7eb9-a613-5bbc9ecf1db3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019d2bfc-45ae-78c9-913b-944dfc61f8ff" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-45ae-7eb9-a613-5bbc9ecf1db3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019d2bfc-45ae-7eb9-a613-5bbc9ecf1db3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-45ae-7eb9-a613-5bbc9ecf1db3" xlink:to="loc_us-gaap_RelatedPartyDomain_019d2bfc-45ae-7eb9-a613-5bbc9ecf1db3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019d2bfc-45ae-75ff-988e-80f9be298fdb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-45ae-7eb9-a613-5bbc9ecf1db3" xlink:to="loc_us-gaap_RelatedPartyDomain_019d2bfc-45ae-75ff-988e-80f9be298fdb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019d2bfc-45ae-7a69-8526-14073516f5a6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019d2bfc-45ae-75ff-988e-80f9be298fdb" xlink:to="loc_us-gaap_RelatedPartyMember_019d2bfc-45ae-7a69-8526-14073516f5a6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonrelatedPartyMember_019d2bfc-45ae-7ac1-8467-d5df87dbf2f4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonrelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019d2bfc-45ae-75ff-988e-80f9be298fdb" xlink:to="loc_us-gaap_NonrelatedPartyMember_019d2bfc-45ae-7ac1-8467-d5df87dbf2f4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019d2bfc-45ae-7926-bb77-6e0eadd1490d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019d2bfc-45ae-76b5-8a34-6c5e4e914f4b" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019d2bfc-45ae-7926-bb77-6e0eadd1490d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSettlementContractsFairValueMethodRealizedAndUnrealizedGainLoss_019d2bfc-45ae-740d-afb6-1ec57762d07a" xlink:href="abx-20260331.xsd#abx_LifeSettlementContractsFairValueMethodRealizedAndUnrealizedGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019d2bfc-45ae-76b5-8a34-6c5e4e914f4b" xlink:to="loc_abx_LifeSettlementContractsFairValueMethodRealizedAndUnrealizedGainLoss_019d2bfc-45ae-740d-afb6-1ec57762d07a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InsuranceCommissionsAndFees_019d2bfc-45ae-789f-ba93-acfda68e68ff" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InsuranceCommissionsAndFees"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019d2bfc-45ae-76b5-8a34-6c5e4e914f4b" xlink:to="loc_us-gaap_InsuranceCommissionsAndFees_019d2bfc-45ae-789f-ba93-acfda68e68ff" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019d2bfc-45ae-7afc-81c8-836da1c2da8c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019d2bfc-45ae-76b5-8a34-6c5e4e914f4b" xlink:to="loc_us-gaap_Revenues_019d2bfc-45ae-7afc-81c8-836da1c2da8c" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/REVENUESDisaggregationofLifeSolutionsRevenueDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#REVENUESDisaggregationofLifeSolutionsRevenueDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/REVENUESDisaggregationofLifeSolutionsRevenueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019e02d5-9c42-73ca-9ce9-66de091579c1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_019e02d5-9c42-76f9-b729-f419ad4b3e57" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019e02d5-9c42-73ca-9ce9-66de091579c1" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019e02d5-9c42-76f9-b729-f419ad4b3e57" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019e02f5-8ae0-735d-b284-56946584213b" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019e02d5-9c42-76f9-b729-f419ad4b3e57" xlink:to="loc_srt_ProductOrServiceAxis_019e02f5-8ae0-735d-b284-56946584213b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019e02f5-8ae0-735d-b284-56946584213b_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019e02f5-8ae0-735d-b284-56946584213b" xlink:to="loc_srt_ProductsAndServicesDomain_019e02f5-8ae0-735d-b284-56946584213b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019e02f5-8ae0-7498-9ee7-36364e5cf8bc" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019e02f5-8ae0-735d-b284-56946584213b" xlink:to="loc_srt_ProductsAndServicesDomain_019e02f5-8ae0-7498-9ee7-36364e5cf8bc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSolutionsMember_019e02f5-8ae0-726d-8a15-2baa8a8823bd" xlink:href="abx-20260331.xsd#abx_LifeSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e02f5-8ae0-7498-9ee7-36364e5cf8bc" xlink:to="loc_abx_LifeSolutionsMember_019e02f5-8ae0-726d-8a15-2baa8a8823bd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019e02d5-9c42-7465-8c8c-e87e8485a3a4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019e02d5-9c42-76f9-b729-f419ad4b3e57" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019e02d5-9c42-7465-8c8c-e87e8485a3a4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019e02d5-9c42-7465-8c8c-e87e8485a3a4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019e02d5-9c42-7465-8c8c-e87e8485a3a4" xlink:to="loc_us-gaap_RelatedPartyDomain_019e02d5-9c42-7465-8c8c-e87e8485a3a4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019e02d5-9c42-7d20-995e-4b470e7cb033" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019e02d5-9c42-7465-8c8c-e87e8485a3a4" xlink:to="loc_us-gaap_RelatedPartyDomain_019e02d5-9c42-7d20-995e-4b470e7cb033" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonrelatedPartyMember_019e02d5-9c42-7993-9fea-daa006e53320" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonrelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019e02d5-9c42-7d20-995e-4b470e7cb033" xlink:to="loc_us-gaap_NonrelatedPartyMember_019e02d5-9c42-7993-9fea-daa006e53320" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019e02d5-9c42-7fef-96b3-f2981fda1d79" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019e02d5-9c42-7d20-995e-4b470e7cb033" xlink:to="loc_us-gaap_RelatedPartyMember_019e02d5-9c42-7fef-96b3-f2981fda1d79" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LifeSettlementContractsFairValueMethodGainLoss_019e02d5-9c42-7f59-bd52-3fb8da536b73" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LifeSettlementContractsFairValueMethodGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019e02d5-9c42-73ca-9ce9-66de091579c1" xlink:to="loc_us-gaap_LifeSettlementContractsFairValueMethodGainLoss_019e02d5-9c42-7f59-bd52-3fb8da536b73" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSettlementContractsFairValueMethodPremiumsPaidOnSoldPolicies_019e02d5-9c42-72ef-8447-85f22385c664" xlink:href="abx-20260331.xsd#abx_LifeSettlementContractsFairValueMethodPremiumsPaidOnSoldPolicies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019e02d5-9c42-73ca-9ce9-66de091579c1" xlink:to="loc_abx_LifeSettlementContractsFairValueMethodPremiumsPaidOnSoldPolicies_019e02d5-9c42-72ef-8447-85f22385c664" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSettlementContractsFairValueMethodPremiumsPaidOnUnsoldPolicies_019e02d5-9c42-71e6-b571-4483a1d0192f" xlink:href="abx-20260331.xsd#abx_LifeSettlementContractsFairValueMethodPremiumsPaidOnUnsoldPolicies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019e02d5-9c42-73ca-9ce9-66de091579c1" xlink:to="loc_abx_LifeSettlementContractsFairValueMethodPremiumsPaidOnUnsoldPolicies_019e02d5-9c42-71e6-b571-4483a1d0192f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSettlementContractsFairValueMethodReversalOfUnrealizedGainsFromPriorPeriods_019e02d5-9c42-7a28-8dfe-3547479aea9b" xlink:href="abx-20260331.xsd#abx_LifeSettlementContractsFairValueMethodReversalOfUnrealizedGainsFromPriorPeriods"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019e02d5-9c42-73ca-9ce9-66de091579c1" xlink:to="loc_abx_LifeSettlementContractsFairValueMethodReversalOfUnrealizedGainsFromPriorPeriods_019e02d5-9c42-7a28-8dfe-3547479aea9b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LifeSettlementContractsFairValueMethodUnrealizedGainLoss_019e02d5-9c42-73d7-b14b-127175ff3d41" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LifeSettlementContractsFairValueMethodUnrealizedGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019e02d5-9c42-73ca-9ce9-66de091579c1" xlink:to="loc_us-gaap_LifeSettlementContractsFairValueMethodUnrealizedGainLoss_019e02d5-9c42-73d7-b14b-127175ff3d41" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSettlementContractsFairValueMethodRealizedAndUnrealizedGainLoss_019e02d5-9c42-7f03-9931-1c6e049f2af3" xlink:href="abx-20260331.xsd#abx_LifeSettlementContractsFairValueMethodRealizedAndUnrealizedGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019e02d5-9c42-73ca-9ce9-66de091579c1" xlink:to="loc_abx_LifeSettlementContractsFairValueMethodRealizedAndUnrealizedGainLoss_019e02d5-9c42-7f03-9931-1c6e049f2af3" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/REVENUESAssetManagementBalancesDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#REVENUESAssetManagementBalancesDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/REVENUESAssetManagementBalancesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019d2bfc-45ae-757e-8df7-0362c99c3076" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_019d2bfc-45ae-7c43-abc9-eccb9724b20f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019d2bfc-45ae-757e-8df7-0362c99c3076" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019d2bfc-45ae-7c43-abc9-eccb9724b20f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019d2bfc-45ae-719b-b4c9-1856fad386c1" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019d2bfc-45ae-7c43-abc9-eccb9724b20f" xlink:to="loc_srt_ProductOrServiceAxis_019d2bfc-45ae-719b-b4c9-1856fad386c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019d2bfc-45ae-719b-b4c9-1856fad386c1_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019d2bfc-45ae-719b-b4c9-1856fad386c1" xlink:to="loc_srt_ProductsAndServicesDomain_019d2bfc-45ae-719b-b4c9-1856fad386c1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019d2bfc-45ae-75b9-b39f-2091ce380c99" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019d2bfc-45ae-719b-b4c9-1856fad386c1" xlink:to="loc_srt_ProductsAndServicesDomain_019d2bfc-45ae-75b9-b39f-2091ce380c99" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_ManagementAndPerformanceFeeMember_019d2bfc-45ae-76e4-a2f9-04f8705a53a9" xlink:href="abx-20260331.xsd#abx_ManagementAndPerformanceFeeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019d2bfc-45ae-75b9-b39f-2091ce380c99" xlink:to="loc_abx_ManagementAndPerformanceFeeMember_019d2bfc-45ae-76e4-a2f9-04f8705a53a9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_RetrocessionFeeMember_019d2bfc-45ae-7f99-80e9-5c9b5ac95981" xlink:href="abx-20260331.xsd#abx_RetrocessionFeeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019d2bfc-45ae-75b9-b39f-2091ce380c99" xlink:to="loc_abx_RetrocessionFeeMember_019d2bfc-45ae-7f99-80e9-5c9b5ac95981" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-45ae-7b78-905c-39ce4a2ef064" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019d2bfc-45ae-7c43-abc9-eccb9724b20f" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-45ae-7b78-905c-39ce4a2ef064" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019d2bfc-45ae-7b78-905c-39ce4a2ef064_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-45ae-7b78-905c-39ce4a2ef064" xlink:to="loc_us-gaap_RelatedPartyDomain_019d2bfc-45ae-7b78-905c-39ce4a2ef064_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019d2bfc-45ae-7f9e-bbb5-4298345f602c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-45ae-7b78-905c-39ce4a2ef064" xlink:to="loc_us-gaap_RelatedPartyDomain_019d2bfc-45ae-7f9e-bbb5-4298345f602c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019d2bfc-45ae-7f42-a873-adafb4484eec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019d2bfc-45ae-7f9e-bbb5-4298345f602c" xlink:to="loc_us-gaap_RelatedPartyMember_019d2bfc-45ae-7f42-a873-adafb4484eec" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_ManagementAndPerformanceFeeReceivablesAbstract_019d2bfc-45ae-7674-91d5-c15210784feb" xlink:href="abx-20260331.xsd#abx_ManagementAndPerformanceFeeReceivablesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019d2bfc-45ae-757e-8df7-0362c99c3076" xlink:to="loc_abx_ManagementAndPerformanceFeeReceivablesAbstract_019d2bfc-45ae-7674-91d5-c15210784feb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_019d2bfc-45ae-772b-9af8-efccb46c312e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_ManagementAndPerformanceFeeReceivablesAbstract_019d2bfc-45ae-7674-91d5-c15210784feb" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_019d2bfc-45ae-772b-9af8-efccb46c312e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetNoncurrent_019d2bfc-45ae-7392-b3b3-da397cbfa586" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableNetNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_ManagementAndPerformanceFeeReceivablesAbstract_019d2bfc-45ae-7674-91d5-c15210784feb" xlink:to="loc_us-gaap_AccountsReceivableNetNoncurrent_019d2bfc-45ae-7392-b3b3-da397cbfa586" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNet_019d2bfc-45ae-7c59-8d8c-a98db968aaf9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_ManagementAndPerformanceFeeReceivablesAbstract_019d2bfc-45ae-7674-91d5-c15210784feb" xlink:to="loc_us-gaap_AccountsReceivableNet_019d2bfc-45ae-7c59-8d8c-a98db968aaf9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_RetrocessionFeePayableAbstract_019d2bfc-45ae-787a-98c1-9963ab691300" xlink:href="abx-20260331.xsd#abx_RetrocessionFeePayableAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019d2bfc-45ae-757e-8df7-0362c99c3076" xlink:to="loc_abx_RetrocessionFeePayableAbstract_019d2bfc-45ae-787a-98c1-9963ab691300" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesCurrent_019d2bfc-45ae-764a-8ab6-f5472e347caf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_RetrocessionFeePayableAbstract_019d2bfc-45ae-787a-98c1-9963ab691300" xlink:to="loc_us-gaap_OtherLiabilitiesCurrent_019d2bfc-45ae-764a-8ab6-f5472e347caf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_RetrocessionFeesPayableNoncurrent_019d2bfc-45ae-7a5d-9b3c-17a6ccb12b73" xlink:href="abx-20260331.xsd#abx_RetrocessionFeesPayableNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_RetrocessionFeePayableAbstract_019d2bfc-45ae-787a-98c1-9963ab691300" xlink:to="loc_abx_RetrocessionFeesPayableNoncurrent_019d2bfc-45ae-7a5d-9b3c-17a6ccb12b73" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_RetrocessionFeePayable_019d2bfc-45ae-7c3c-b955-dee81e97bbcf" xlink:href="abx-20260331.xsd#abx_RetrocessionFeePayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_RetrocessionFeePayableAbstract_019d2bfc-45ae-787a-98c1-9963ab691300" xlink:to="loc_abx_RetrocessionFeePayable_019d2bfc-45ae-7c3c-b955-dee81e97bbcf" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/PROPERTYANDEQUIPMENTNETDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#PROPERTYANDEQUIPMENTNETDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/PROPERTYANDEQUIPMENTNETDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019d2bfc-45ae-7b1d-881e-5ba5c0aec829" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019d2bfc-45ae-74ca-9b85-b282bc6b9cd3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019d2bfc-45ae-7b1d-881e-5ba5c0aec829" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019d2bfc-45ae-74ca-9b85-b282bc6b9cd3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019d2bfc-45ae-7dad-9346-800866c86008" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019d2bfc-45ae-74ca-9b85-b282bc6b9cd3" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019d2bfc-45ae-7dad-9346-800866c86008" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019d2bfc-45ae-7dad-9346-800866c86008_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019d2bfc-45ae-7dad-9346-800866c86008" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019d2bfc-45ae-7dad-9346-800866c86008_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019d2bfc-45ae-74c9-b0fb-15fafbee0d9f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019d2bfc-45ae-7dad-9346-800866c86008" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019d2bfc-45ae-74c9-b0fb-15fafbee0d9f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComputerEquipmentMember_019d2bfc-45ae-7524-85ae-64504a9d5c88" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComputerEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019d2bfc-45ae-74c9-b0fb-15fafbee0d9f" xlink:to="loc_us-gaap_ComputerEquipmentMember_019d2bfc-45ae-7524-85ae-64504a9d5c88" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_019d2bfc-45ae-72d8-ae80-84b57390a9bd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FurnitureAndFixturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019d2bfc-45ae-74c9-b0fb-15fafbee0d9f" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_019d2bfc-45ae-72d8-ae80-84b57390a9bd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseholdImprovementsMember_019d2bfc-45ae-79fd-9060-04c297ed6329" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseholdImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019d2bfc-45ae-74c9-b0fb-15fafbee0d9f" xlink:to="loc_us-gaap_LeaseholdImprovementsMember_019d2bfc-45ae-79fd-9060-04c297ed6329" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_019d2bfc-45ae-701d-a222-de582a4a81f0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019d2bfc-45ae-7b1d-881e-5ba5c0aec829" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_019d2bfc-45ae-701d-a222-de582a4a81f0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_019d2bfc-45ae-78e3-94e0-6262fbfbe8b6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019d2bfc-45ae-7b1d-881e-5ba5c0aec829" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_019d2bfc-45ae-78e3-94e0-6262fbfbe8b6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_019d2bfc-45ae-7cd8-8392-14cbcddad963" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019d2bfc-45ae-7b1d-881e-5ba5c0aec829" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_019d2bfc-45ae-7cd8-8392-14cbcddad963" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Depreciation_019d2bfc-45ae-7abc-91a7-5c9889e46d6d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Depreciation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019d2bfc-45ae-7b1d-881e-5ba5c0aec829" xlink:to="loc_us-gaap_Depreciation_019d2bfc-45ae-7abc-91a7-5c9889e46d6d" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/GOODWILLANDOTHERINTANGIBLEASSETSChangesinGoodwillbyReportableSegmentsDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#GOODWILLANDOTHERINTANGIBLEASSETSChangesinGoodwillbyReportableSegmentsDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/GOODWILLANDOTHERINTANGIBLEASSETSChangesinGoodwillbyReportableSegmentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_019d2bfc-45ae-7eef-b1b5-c252128772be" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_019d2bfc-45ae-77d2-9574-5d4d8ebaf22e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfGoodwillTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_019d2bfc-45ae-7eef-b1b5-c252128772be" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_019d2bfc-45ae-77d2-9574-5d4d8ebaf22e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019d2bfc-45ae-7811-b1fe-a501f280bbb7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_019d2bfc-45ae-77d2-9574-5d4d8ebaf22e" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019d2bfc-45ae-7811-b1fe-a501f280bbb7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019d2bfc-45ae-7811-b1fe-a501f280bbb7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019d2bfc-45ae-7811-b1fe-a501f280bbb7" xlink:to="loc_us-gaap_SegmentDomain_019d2bfc-45ae-7811-b1fe-a501f280bbb7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019d2bfc-45ae-7bcb-96e2-70ae49faff8d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019d2bfc-45ae-7811-b1fe-a501f280bbb7" xlink:to="loc_us-gaap_SegmentDomain_019d2bfc-45ae-7bcb-96e2-70ae49faff8d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSolutionsSegmentMember_019d2bfc-45ae-726e-8577-dd738b4b6cd5" xlink:href="abx-20260331.xsd#abx_LifeSolutionsSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019d2bfc-45ae-7bcb-96e2-70ae49faff8d" xlink:to="loc_abx_LifeSolutionsSegmentMember_019d2bfc-45ae-726e-8577-dd738b4b6cd5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_ActiveManagementSegmentMember_019d2bfc-45ae-715f-9ccd-6c64005d48e4" xlink:href="abx-20260331.xsd#abx_ActiveManagementSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019d2bfc-45ae-7bcb-96e2-70ae49faff8d" xlink:to="loc_abx_ActiveManagementSegmentMember_019d2bfc-45ae-715f-9ccd-6c64005d48e4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillRollForward_019d2bfc-45ae-7a84-a6dd-6076a0680c29" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_019d2bfc-45ae-7eef-b1b5-c252128772be" xlink:to="loc_us-gaap_GoodwillRollForward_019d2bfc-45ae-7a84-a6dd-6076a0680c29" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019d2bfc-45ae-71fb-a3e3-fc2936745e06" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_019d2bfc-45ae-7a84-a6dd-6076a0680c29" xlink:to="loc_us-gaap_Goodwill_019d2bfc-45ae-71fb-a3e3-fc2936745e06" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod_019d2bfc-45ae-7704-b3b7-4f5a598ae2ad" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillAcquiredDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_019d2bfc-45ae-7a84-a6dd-6076a0680c29" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_019d2bfc-45ae-7704-b3b7-4f5a598ae2ad" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_019d2bfc-45ae-7d8f-9c6d-4abe4a738846" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillPurchaseAccountingAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_019d2bfc-45ae-7a84-a6dd-6076a0680c29" xlink:to="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_019d2bfc-45ae-7d8f-9c6d-4abe4a738846" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019d2bfc-45ae-7014-90d6-4b54bb37cc4d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/GOODWILLANDOTHERINTANGIBLEASSETSIntangibleAssetsAcquiredDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#GOODWILLANDOTHERINTANGIBLEASSETSIntangibleAssetsAcquiredDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/GOODWILLANDOTHERINTANGIBLEASSETSIntangibleAssetsAcquiredDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_abx_ScheduleOfIntangibleAssetsLineItems_019d2bfc-45ae-763d-bcaa-07bcceeb1552" xlink:href="abx-20260331.xsd#abx_ScheduleOfIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_ScheduleOfIntangibleAssetsTable_019d2bfc-45ae-7cdb-b6cb-f5a55c55884c" xlink:href="abx-20260331.xsd#abx_ScheduleOfIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_abx_ScheduleOfIntangibleAssetsLineItems_019d2bfc-45ae-763d-bcaa-07bcceeb1552" xlink:to="loc_abx_ScheduleOfIntangibleAssetsTable_019d2bfc-45ae-7cdb-b6cb-f5a55c55884c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019d2bfc-45ae-72f4-9039-185ffb84ffd7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_abx_ScheduleOfIntangibleAssetsTable_019d2bfc-45ae-7cdb-b6cb-f5a55c55884c" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019d2bfc-45ae-72f4-9039-185ffb84ffd7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-72f4-9039-185ffb84ffd7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019d2bfc-45ae-72f4-9039-185ffb84ffd7" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-72f4-9039-185ffb84ffd7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-7d40-a87f-4eeb2195a489" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019d2bfc-45ae-72f4-9039-185ffb84ffd7" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-7d40-a87f-4eeb2195a489" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_ManagementAgreementsMember_019d2bfc-45ae-7a81-9e08-15ce18b0d116" xlink:href="abx-20260331.xsd#abx_ManagementAgreementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-7d40-a87f-4eeb2195a489" xlink:to="loc_abx_ManagementAgreementsMember_019d2bfc-45ae-7a81-9e08-15ce18b0d116" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_019d2bfc-45ae-7cb0-b0de-d1c5354cca38" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-7d40-a87f-4eeb2195a489" xlink:to="loc_us-gaap_CustomerRelationshipsMember_019d2bfc-45ae-7cb0-b0de-d1c5354cca38" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncompeteAgreementsMember_019d2bfc-45ae-7503-97b5-de93cf73ab19" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoncompeteAgreementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-7d40-a87f-4eeb2195a489" xlink:to="loc_us-gaap_NoncompeteAgreementsMember_019d2bfc-45ae-7503-97b5-de93cf73ab19" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TechnologyBasedIntangibleAssetsMember_019d2bfc-45ae-7be2-85c7-f05e90f57661" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TechnologyBasedIntangibleAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-7d40-a87f-4eeb2195a489" xlink:to="loc_us-gaap_TechnologyBasedIntangibleAssetsMember_019d2bfc-45ae-7be2-85c7-f05e90f57661" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_019d2bfc-45ae-7080-b043-e7a444772744" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-7d40-a87f-4eeb2195a489" xlink:to="loc_us-gaap_TradeNamesMember_019d2bfc-45ae-7080-b043-e7a444772744" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019d2bfc-45ae-7cb8-b677-75dd558bbdec" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_abx_ScheduleOfIntangibleAssetsTable_019d2bfc-45ae-7cdb-b6cb-f5a55c55884c" xlink:to="loc_srt_RangeAxis_019d2bfc-45ae-7cb8-b677-75dd558bbdec" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019d2bfc-45ae-7cb8-b677-75dd558bbdec_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019d2bfc-45ae-7cb8-b677-75dd558bbdec" xlink:to="loc_srt_RangeMember_019d2bfc-45ae-7cb8-b677-75dd558bbdec_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019d2bfc-45ae-799e-bdaa-74460ab489bd" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019d2bfc-45ae-7cb8-b677-75dd558bbdec" xlink:to="loc_srt_RangeMember_019d2bfc-45ae-799e-bdaa-74460ab489bd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019d2bfc-45ae-73ad-ba45-7e5df5d495cd" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019d2bfc-45ae-799e-bdaa-74460ab489bd" xlink:to="loc_srt_MinimumMember_019d2bfc-45ae-73ad-ba45-7e5df5d495cd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019d2bfc-45ae-7efb-8f4f-7e7521fdcf20" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019d2bfc-45ae-799e-bdaa-74460ab489bd" xlink:to="loc_srt_MaximumMember_019d2bfc-45ae-7efb-8f4f-7e7521fdcf20" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_019d2bfc-45ae-78b7-8de5-69a952236a69" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_abx_ScheduleOfIntangibleAssetsTable_019d2bfc-45ae-7cdb-b6cb-f5a55c55884c" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_019d2bfc-45ae-78b7-8de5-69a952236a69" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-78b7-8de5-69a952236a69_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_019d2bfc-45ae-78b7-8de5-69a952236a69" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-78b7-8de5-69a952236a69_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-77a4-8472-396cb758fde0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_019d2bfc-45ae-78b7-8de5-69a952236a69" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-77a4-8472-396cb758fde0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LicensingAgreementsMember_019d2bfc-45ae-78f6-a70a-43a8a8f7b48f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LicensingAgreementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-77a4-8472-396cb758fde0" xlink:to="loc_us-gaap_LicensingAgreementsMember_019d2bfc-45ae-78f6-a70a-43a8a8f7b48f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_019d2bfc-45ae-7bf8-919f-97b6489aa0d5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-77a4-8472-396cb758fde0" xlink:to="loc_us-gaap_TradeNamesMember_019d2bfc-45ae-7bf8-919f-97b6489aa0d5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_019d2bfc-45ae-7a35-87b9-abd877e2892e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_ScheduleOfIntangibleAssetsLineItems_019d2bfc-45ae-763d-bcaa-07bcceeb1552" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_019d2bfc-45ae-7a35-87b9-abd877e2892e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_019d2bfc-45ae-77c2-a175-297400d5530c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_ScheduleOfIntangibleAssetsLineItems_019d2bfc-45ae-763d-bcaa-07bcceeb1552" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_019d2bfc-45ae-77c2-a175-297400d5530c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_019dfd1a-2fbb-7a39-a458-c868c83ec641" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_ScheduleOfIntangibleAssetsLineItems_019d2bfc-45ae-763d-bcaa-07bcceeb1552" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_019dfd1a-2fbb-7a39-a458-c868c83ec641" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/GOODWILLANDOTHERINTANGIBLEASSETSIntangibleAssetsandAccumulatedAmortizationDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#GOODWILLANDOTHERINTANGIBLEASSETSIntangibleAssetsandAccumulatedAmortizationDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/GOODWILLANDOTHERINTANGIBLEASSETSIntangibleAssetsandAccumulatedAmortizationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_abx_ScheduleOfIntangibleAssetsLineItems_019d2bfc-45ae-7d19-8708-9b2caabb31de" xlink:href="abx-20260331.xsd#abx_ScheduleOfIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_ScheduleOfIntangibleAssetsTable_019d2bfc-45ae-7245-be0c-768f9be94758" xlink:href="abx-20260331.xsd#abx_ScheduleOfIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_abx_ScheduleOfIntangibleAssetsLineItems_019d2bfc-45ae-7d19-8708-9b2caabb31de" xlink:to="loc_abx_ScheduleOfIntangibleAssetsTable_019d2bfc-45ae-7245-be0c-768f9be94758" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019d2bfc-45ae-721c-9b1e-189fb9824676" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_abx_ScheduleOfIntangibleAssetsTable_019d2bfc-45ae-7245-be0c-768f9be94758" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019d2bfc-45ae-721c-9b1e-189fb9824676" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-721c-9b1e-189fb9824676_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019d2bfc-45ae-721c-9b1e-189fb9824676" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-721c-9b1e-189fb9824676_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-7e98-a651-3e6e477ccce7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019d2bfc-45ae-721c-9b1e-189fb9824676" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-7e98-a651-3e6e477ccce7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_FiniteLivedIntangibleAssetsExcludingOtherInsignificantAmountMember_019d2bfc-45ae-78dc-aba2-a90550a60a88" xlink:href="abx-20260331.xsd#abx_FiniteLivedIntangibleAssetsExcludingOtherInsignificantAmountMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-7e98-a651-3e6e477ccce7" xlink:to="loc_abx_FiniteLivedIntangibleAssetsExcludingOtherInsignificantAmountMember_019d2bfc-45ae-78dc-aba2-a90550a60a88" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_ManagementAgreementsMember_019d2bfc-45ae-70dc-ad95-85f856672468" xlink:href="abx-20260331.xsd#abx_ManagementAgreementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_FiniteLivedIntangibleAssetsExcludingOtherInsignificantAmountMember_019d2bfc-45ae-78dc-aba2-a90550a60a88" xlink:to="loc_abx_ManagementAgreementsMember_019d2bfc-45ae-70dc-ad95-85f856672468" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_019d2bfc-45ae-77c8-bf83-5d4aff99e199" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_FiniteLivedIntangibleAssetsExcludingOtherInsignificantAmountMember_019d2bfc-45ae-78dc-aba2-a90550a60a88" xlink:to="loc_us-gaap_CustomerRelationshipsMember_019d2bfc-45ae-77c8-bf83-5d4aff99e199" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncompeteAgreementsMember_019d2bfc-45ae-77ce-95c0-7b284cca1b79" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoncompeteAgreementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_FiniteLivedIntangibleAssetsExcludingOtherInsignificantAmountMember_019d2bfc-45ae-78dc-aba2-a90550a60a88" xlink:to="loc_us-gaap_NoncompeteAgreementsMember_019d2bfc-45ae-77ce-95c0-7b284cca1b79" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TechnologyBasedIntangibleAssetsMember_019d2bfc-45ae-728f-adef-2b6c174c994b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TechnologyBasedIntangibleAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_FiniteLivedIntangibleAssetsExcludingOtherInsignificantAmountMember_019d2bfc-45ae-78dc-aba2-a90550a60a88" xlink:to="loc_us-gaap_TechnologyBasedIntangibleAssetsMember_019d2bfc-45ae-728f-adef-2b6c174c994b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_019d2bfc-45ae-7256-a0ed-8d3bc000b52e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_FiniteLivedIntangibleAssetsExcludingOtherInsignificantAmountMember_019d2bfc-45ae-78dc-aba2-a90550a60a88" xlink:to="loc_us-gaap_TradeNamesMember_019d2bfc-45ae-7256-a0ed-8d3bc000b52e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_019d2bfc-45ae-78d6-a4b9-120e8aa4fa7f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_abx_ScheduleOfIntangibleAssetsTable_019d2bfc-45ae-7245-be0c-768f9be94758" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_019d2bfc-45ae-78d6-a4b9-120e8aa4fa7f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-78d6-a4b9-120e8aa4fa7f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_019d2bfc-45ae-78d6-a4b9-120e8aa4fa7f" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-78d6-a4b9-120e8aa4fa7f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-7687-9621-5f14a07e8b92" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_019d2bfc-45ae-78d6-a4b9-120e8aa4fa7f" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-7687-9621-5f14a07e8b92" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_IndefiniteLivedIntangibleAssetsExcludingOtherInsignificantAmountMember_019d2bfc-45ae-70dd-bb20-736841631c1d" xlink:href="abx-20260331.xsd#abx_IndefiniteLivedIntangibleAssetsExcludingOtherInsignificantAmountMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_019d2bfc-45ae-7687-9621-5f14a07e8b92" xlink:to="loc_abx_IndefiniteLivedIntangibleAssetsExcludingOtherInsignificantAmountMember_019d2bfc-45ae-70dd-bb20-736841631c1d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LicensingAgreementsMember_019d2bfc-45ae-7161-9cb4-283e32683435" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LicensingAgreementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_IndefiniteLivedIntangibleAssetsExcludingOtherInsignificantAmountMember_019d2bfc-45ae-70dd-bb20-736841631c1d" xlink:to="loc_us-gaap_LicensingAgreementsMember_019d2bfc-45ae-7161-9cb4-283e32683435" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_019d2bfc-45ae-7efc-89e2-45533043ca60" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_IndefiniteLivedIntangibleAssetsExcludingOtherInsignificantAmountMember_019d2bfc-45ae-70dd-bb20-736841631c1d" xlink:to="loc_us-gaap_TradeNamesMember_019d2bfc-45ae-7efc-89e2-45533043ca60" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019d2bfc-45ae-7998-8b45-6ad05f94691b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_ScheduleOfIntangibleAssetsLineItems_019d2bfc-45ae-7d19-8708-9b2caabb31de" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019d2bfc-45ae-7998-8b45-6ad05f94691b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019d2bfc-45ae-7a0c-8da5-790de42884b0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_ScheduleOfIntangibleAssetsLineItems_019d2bfc-45ae-7d19-8708-9b2caabb31de" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019d2bfc-45ae-7a0c-8da5-790de42884b0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019d2bfc-45ae-7b90-84eb-85ed379fdf43" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_ScheduleOfIntangibleAssetsLineItems_019d2bfc-45ae-7d19-8708-9b2caabb31de" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019d2bfc-45ae-7b90-84eb-85ed379fdf43" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_019d2bfc-45ae-793f-8cff-d8ba62e4e50c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_ScheduleOfIntangibleAssetsLineItems_019d2bfc-45ae-7d19-8708-9b2caabb31de" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_019d2bfc-45ae-793f-8cff-d8ba62e4e50c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_019d2bfc-45ae-7b3f-9ed3-40d22d023f27" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntangibleAssetsGrossExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_ScheduleOfIntangibleAssetsLineItems_019d2bfc-45ae-7d19-8708-9b2caabb31de" xlink:to="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_019d2bfc-45ae-7b3f-9ed3-40d22d023f27" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_019d2bfc-45ae-7b3a-af18-3d41363eb22d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_ScheduleOfIntangibleAssetsLineItems_019d2bfc-45ae-7d19-8708-9b2caabb31de" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_019d2bfc-45ae-7b3a-af18-3d41363eb22d" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/AVAILABLEFORSALESECURITIESATFAIRVALUENarrativeDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#AVAILABLEFORSALESECURITIESATFAIRVALUENarrativeDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/AVAILABLEFORSALESECURITIESATFAIRVALUENarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_019dd47c-72f4-72d6-bde5-a233357e8484" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_019d2bfc-45ae-7453-a77f-7135df747e57" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_019dd47c-72f4-72d6-bde5-a233357e8484" xlink:to="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_019d2bfc-45ae-7453-a77f-7135df747e57" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_019dd47c-72f4-70d1-8acc-2d34b1ebc75b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_019d2bfc-45ae-7453-a77f-7135df747e57" xlink:to="loc_us-gaap_FinancialInstrumentAxis_019dd47c-72f4-70d1-8acc-2d34b1ebc75b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019dd47c-72f4-70d1-8acc-2d34b1ebc75b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019dd47c-72f4-70d1-8acc-2d34b1ebc75b" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019dd47c-72f4-70d1-8acc-2d34b1ebc75b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019dd47c-72f4-7d03-a8ef-ccb3896c2544" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019dd47c-72f4-70d1-8acc-2d34b1ebc75b" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019dd47c-72f4-7d03-a8ef-ccb3896c2544" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_ConvertiblePromissoryNoteOneMember_019dd47c-72f4-7e0a-8128-3829ec3a421c" xlink:href="abx-20260331.xsd#abx_ConvertiblePromissoryNoteOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019dd47c-72f4-7d03-a8ef-ccb3896c2544" xlink:to="loc_abx_ConvertiblePromissoryNoteOneMember_019dd47c-72f4-7e0a-8128-3829ec3a421c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_ConvertiblePromissoryNoteTwoMember_019dd47c-72f4-700c-adc3-df9798fde743" xlink:href="abx-20260331.xsd#abx_ConvertiblePromissoryNoteTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019dd47c-72f4-7d03-a8ef-ccb3896c2544" xlink:to="loc_abx_ConvertiblePromissoryNoteTwoMember_019dd47c-72f4-700c-adc3-df9798fde743" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_NumberOfEntitiesInWhichConvertibleNotesAreHeld_019dd47c-72f4-7af6-9743-5dfc9443b50a" xlink:href="abx-20260331.xsd#abx_NumberOfEntitiesInWhichConvertibleNotesAreHeld"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_019dd47c-72f4-72d6-bde5-a233357e8484" xlink:to="loc_abx_NumberOfEntitiesInWhichConvertibleNotesAreHeld_019dd47c-72f4-7af6-9743-5dfc9443b50a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_DebtSecuritiesAvailableForSalePrincipalAmount_019dd47c-72f4-73f9-9a55-54d0ab3d9d87" xlink:href="abx-20260331.xsd#abx_DebtSecuritiesAvailableForSalePrincipalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_019dd47c-72f4-72d6-bde5-a233357e8484" xlink:to="loc_abx_DebtSecuritiesAvailableForSalePrincipalAmount_019dd47c-72f4-73f9-9a55-54d0ab3d9d87" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleWeightedAverageYield_019dd47c-72f4-7e84-8ddc-c25bf04827bc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleWeightedAverageYield"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_019dd47c-72f4-72d6-bde5-a233357e8484" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleWeightedAverageYield_019dd47c-72f4-7e84-8ddc-c25bf04827bc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_DebtSecuritiesAvailableForSaleAllowanceForCreditLossPercentage_019dd47c-72f4-7175-b8b5-e5a2680f1f73" xlink:href="abx-20260331.xsd#abx_DebtSecuritiesAvailableForSaleAllowanceForCreditLossPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_019dd47c-72f4-72d6-bde5-a233357e8484" xlink:to="loc_abx_DebtSecuritiesAvailableForSaleAllowanceForCreditLossPercentage_019dd47c-72f4-7175-b8b5-e5a2680f1f73" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019df958-f02b-77f2-927d-d5bf0cb2369e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_019dd47c-72f4-72d6-bde5-a233357e8484" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019df958-f02b-77f2-927d-d5bf0cb2369e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent_019dd47c-72f4-7a25-8b4b-a35e9613f6f9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_019dd47c-72f4-72d6-bde5-a233357e8484" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent_019dd47c-72f4-7a25-8b4b-a35e9613f6f9" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLossNoncurrent_019dd47c-72f4-71c7-a807-87595625ffec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLossNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_019dd47c-72f4-72d6-bde5-a233357e8484" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLossNoncurrent_019dd47c-72f4-71c7-a807-87595625ffec" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotPreviouslyRecorded_019dd61e-2d7a-75ad-8283-84978a95ff39" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotPreviouslyRecorded"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_019dd47c-72f4-72d6-bde5-a233357e8484" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotPreviouslyRecorded_019dd61e-2d7a-75ad-8283-84978a95ff39" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeDebtSecuritiesAvailableForSaleOperating_019dd47c-b85a-7b5d-add4-8e3b86941ce0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeDebtSecuritiesAvailableForSaleOperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_019dd47c-72f4-72d6-bde5-a233357e8484" xlink:to="loc_us-gaap_InterestIncomeDebtSecuritiesAvailableForSaleOperating_019dd47c-b85a-7b5d-add4-8e3b86941ce0" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/AVAILABLEFORSALESECURITIESATFAIRVALUEDebtSecuritiesAvailableforSaleAllowanceforCreditLossDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#AVAILABLEFORSALESECURITIESATFAIRVALUEDebtSecuritiesAvailableforSaleAllowanceforCreditLossDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/AVAILABLEFORSALESECURITIESATFAIRVALUEDebtSecuritiesAvailableforSaleAllowanceforCreditLossDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableforsaleAllowanceForCreditLossLineItems_019d2bfc-45af-79cc-a7c7-da956edcf68b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableforsaleAllowanceForCreditLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossTable_019d2bfc-45af-780e-a755-ee08cb52a577" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtSecuritiesAvailableforsaleAllowanceForCreditLossLineItems_019d2bfc-45af-79cc-a7c7-da956edcf68b" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossTable_019d2bfc-45af-780e-a755-ee08cb52a577" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_019d2bfc-45af-74c0-a943-3b653a6bebe5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossTable_019d2bfc-45af-780e-a755-ee08cb52a577" xlink:to="loc_us-gaap_FinancialInstrumentAxis_019d2bfc-45af-74c0-a943-3b653a6bebe5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019d2bfc-45af-74c0-a943-3b653a6bebe5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019d2bfc-45af-74c0-a943-3b653a6bebe5" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019d2bfc-45af-74c0-a943-3b653a6bebe5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019d2bfc-45af-7db8-a6ce-9b91d2aa81aa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019d2bfc-45af-74c0-a943-3b653a6bebe5" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019d2bfc-45af-7db8-a6ce-9b91d2aa81aa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_ConvertiblePromissoryNoteMember_019d2bfc-45af-7aa4-a35e-0556ade4371b" xlink:href="abx-20260331.xsd#abx_ConvertiblePromissoryNoteMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019d2bfc-45af-7db8-a6ce-9b91d2aa81aa" xlink:to="loc_abx_ConvertiblePromissoryNoteMember_019d2bfc-45af-7aa4-a35e-0556ade4371b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossRollForward_019d2bfc-45af-76ae-99de-4e294ecec356" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtSecuritiesAvailableforsaleAllowanceForCreditLossLineItems_019d2bfc-45af-79cc-a7c7-da956edcf68b" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossRollForward_019d2bfc-45af-76ae-99de-4e294ecec356" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLoss_019d2bfc-45af-7e51-b62b-b3965b16195d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossRollForward_019d2bfc-45af-76ae-99de-4e294ecec356" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLoss_019d2bfc-45af-7e51-b62b-b3965b16195d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotPreviouslyRecorded_019d2bfc-45af-7a83-a11c-49b17439532b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotPreviouslyRecorded"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossRollForward_019d2bfc-45af-76ae-99de-4e294ecec356" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotPreviouslyRecorded_019d2bfc-45af-7a83-a11c-49b17439532b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossWriteoff_019d2bfc-45af-779d-b787-084d2e594d7a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossRollForward_019d2bfc-45af-76ae-99de-4e294ecec356" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossWriteoff_019d2bfc-45af-779d-b787-084d2e594d7a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossRecovery_019d2bfc-45af-7f17-ba5f-17815aba0887" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossRecovery"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossRollForward_019d2bfc-45af-76ae-99de-4e294ecec356" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossRecovery_019d2bfc-45af-7f17-ba5f-17815aba0887" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLoss_019d2bfc-45af-7b7a-a1a8-62b905d5e003" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLoss"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/CONSOLIDATIONOFVARIABLEINTERESTENTITIESDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#CONSOLIDATIONOFVARIABLEINTERESTENTITIESDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/CONSOLIDATIONOFVARIABLEINTERESTENTITIESDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityLineItems_019d2bfc-45af-7e2b-9a9d-c05fb8a0ab89" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableInterestEntityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_019d2bfc-45af-704b-bef9-0829f51b69c5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfVariableInterestEntitiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019d2bfc-45af-7e2b-9a9d-c05fb8a0ab89" xlink:to="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_019d2bfc-45af-704b-bef9-0829f51b69c5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_019d2bfc-45af-78ef-9a00-7c52fb6caf0e" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_019d2bfc-45af-704b-bef9-0829f51b69c5" xlink:to="loc_srt_ConsolidatedEntitiesAxis_019d2bfc-45af-78ef-9a00-7c52fb6caf0e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_019d2bfc-45af-78ef-9a00-7c52fb6caf0e_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_019d2bfc-45af-78ef-9a00-7c52fb6caf0e" xlink:to="loc_srt_ConsolidatedEntitiesDomain_019d2bfc-45af-78ef-9a00-7c52fb6caf0e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_019d2bfc-45af-7ae2-b6cf-190109db304b" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_019d2bfc-45af-78ef-9a00-7c52fb6caf0e" xlink:to="loc_srt_ConsolidatedEntitiesDomain_019d2bfc-45af-7ae2-b6cf-190109db304b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_019d2bfc-45af-79d7-9283-c2b53b5bc31a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableInterestEntityPrimaryBeneficiaryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019d2bfc-45af-7ae2-b6cf-190109db304b" xlink:to="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_019d2bfc-45af-79d7-9283-c2b53b5bc31a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember_019e0921-fc7a-773d-8cb0-f65dcb606355" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019d2bfc-45af-7ae2-b6cf-190109db304b" xlink:to="loc_us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember_019e0921-fc7a-773d-8cb0-f65dcb606355" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019d2bfc-45af-7f45-be72-35911697228a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019d2bfc-45af-7e2b-9a9d-c05fb8a0ab89" xlink:to="loc_us-gaap_Assets_019d2bfc-45af-7f45-be72-35911697228a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019d2bfc-45af-76c9-b074-133d79ee9cfe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019d2bfc-45af-7e2b-9a9d-c05fb8a0ab89" xlink:to="loc_us-gaap_Liabilities_019d2bfc-45af-76c9-b074-133d79ee9cfe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_NumberOfInvestmentFunds_019dfeea-89b7-7099-a410-42a8bd097bef" xlink:href="abx-20260331.xsd#abx_NumberOfInvestmentFunds"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019d2bfc-45af-7e2b-9a9d-c05fb8a0ab89" xlink:to="loc_abx_NumberOfInvestmentFunds_019dfeea-89b7-7099-a410-42a8bd097bef" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_NumberOfInvestmentSubFunds_019dfeea-b89c-7ee4-a148-388a4d3e245b" xlink:href="abx-20260331.xsd#abx_NumberOfInvestmentSubFunds"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019d2bfc-45af-7e2b-9a9d-c05fb8a0ab89" xlink:to="loc_abx_NumberOfInvestmentSubFunds_019dfeea-b89c-7ee4-a148-388a4d3e245b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_VariableInterestEntityQualitativeOrQuantitativeInformationContributedCapital_019e0921-c0c5-7c7b-9993-d36e3df59c3b" xlink:href="abx-20260331.xsd#abx_VariableInterestEntityQualitativeOrQuantitativeInformationContributedCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019d2bfc-45af-7e2b-9a9d-c05fb8a0ab89" xlink:to="loc_abx_VariableInterestEntityQualitativeOrQuantitativeInformationContributedCapital_019e0921-c0c5-7c7b-9993-d36e3df59c3b" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/SEGMENTREPORTINGRevenuebySegmentDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#SEGMENTREPORTINGRevenuebySegmentDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/SEGMENTREPORTINGRevenuebySegmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019d2bfc-45af-722d-bc33-152a19c9e08f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019d2bfc-45af-701a-8910-6f54f0c6e6e2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019d2bfc-45af-722d-bc33-152a19c9e08f" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019d2bfc-45af-701a-8910-6f54f0c6e6e2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019d2bfc-45af-714d-8985-ff8ddee9bfca" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019d2bfc-45af-701a-8910-6f54f0c6e6e2" xlink:to="loc_srt_ConsolidationItemsAxis_019d2bfc-45af-714d-8985-ff8ddee9bfca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019d2bfc-45af-714d-8985-ff8ddee9bfca_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_019d2bfc-45af-714d-8985-ff8ddee9bfca" xlink:to="loc_srt_ConsolidationItemsDomain_019d2bfc-45af-714d-8985-ff8ddee9bfca_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019d2bfc-45af-78d6-b659-28634d028c6f" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_019d2bfc-45af-714d-8985-ff8ddee9bfca" xlink:to="loc_srt_ConsolidationItemsDomain_019d2bfc-45af-78d6-b659-28634d028c6f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019d2bfc-45af-726d-8403-35a754f60082" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019d2bfc-45af-78d6-b659-28634d028c6f" xlink:to="loc_us-gaap_OperatingSegmentsMember_019d2bfc-45af-726d-8403-35a754f60082" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019d2bfc-45af-7934-a459-c5f081cab9c0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019d2bfc-45af-701a-8910-6f54f0c6e6e2" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019d2bfc-45af-7934-a459-c5f081cab9c0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019d2bfc-45af-7934-a459-c5f081cab9c0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019d2bfc-45af-7934-a459-c5f081cab9c0" xlink:to="loc_us-gaap_SegmentDomain_019d2bfc-45af-7934-a459-c5f081cab9c0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019d2bfc-45af-74f8-a380-17ac7848b53a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019d2bfc-45af-7934-a459-c5f081cab9c0" xlink:to="loc_us-gaap_SegmentDomain_019d2bfc-45af-74f8-a380-17ac7848b53a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_AssetManagementSegmentMember_019d2bfc-45af-7650-9a4c-dd19eac832d2" xlink:href="abx-20260331.xsd#abx_AssetManagementSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019d2bfc-45af-74f8-a380-17ac7848b53a" xlink:to="loc_abx_AssetManagementSegmentMember_019d2bfc-45af-7650-9a4c-dd19eac832d2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSolutionsSegmentMember_019d2bfc-45af-731c-8427-4a60f12e11f8" xlink:href="abx-20260331.xsd#abx_LifeSolutionsSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019d2bfc-45af-74f8-a380-17ac7848b53a" xlink:to="loc_abx_LifeSolutionsSegmentMember_019d2bfc-45af-731c-8427-4a60f12e11f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_TechnologyServicesSegmentMember_019d2bfc-45af-72e3-be77-e2fac7c4c976" xlink:href="abx-20260331.xsd#abx_TechnologyServicesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019d2bfc-45af-74f8-a380-17ac7848b53a" xlink:to="loc_abx_TechnologyServicesSegmentMember_019d2bfc-45af-72e3-be77-e2fac7c4c976" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019d2bfc-45af-787f-8c34-394d7b3f0048" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019d2bfc-45af-722d-bc33-152a19c9e08f" xlink:to="loc_us-gaap_Revenues_019d2bfc-45af-787f-8c34-394d7b3f0048" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/SEGMENTREPORTINGCostofRevenueDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#SEGMENTREPORTINGCostofRevenueDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/SEGMENTREPORTINGCostofRevenueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019d2bfc-45af-71de-9d7a-5c76c92e32b7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019d2bfc-45af-721c-a2a4-183213fd8a33" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019d2bfc-45af-71de-9d7a-5c76c92e32b7" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019d2bfc-45af-721c-a2a4-183213fd8a33" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019d2bfc-45af-745f-9e4a-43e1e5da18cd" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019d2bfc-45af-721c-a2a4-183213fd8a33" xlink:to="loc_srt_ConsolidationItemsAxis_019d2bfc-45af-745f-9e4a-43e1e5da18cd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019d2bfc-45af-745f-9e4a-43e1e5da18cd_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_019d2bfc-45af-745f-9e4a-43e1e5da18cd" xlink:to="loc_srt_ConsolidationItemsDomain_019d2bfc-45af-745f-9e4a-43e1e5da18cd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019d2bfc-45af-78d3-b6dd-a58b5fb89bfb" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_019d2bfc-45af-745f-9e4a-43e1e5da18cd" xlink:to="loc_srt_ConsolidationItemsDomain_019d2bfc-45af-78d3-b6dd-a58b5fb89bfb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019d2bfc-45af-74f0-b646-bff227d81084" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019d2bfc-45af-78d3-b6dd-a58b5fb89bfb" xlink:to="loc_us-gaap_OperatingSegmentsMember_019d2bfc-45af-74f0-b646-bff227d81084" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019d2bfc-45af-7c6f-bb1f-67ce09937290" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019d2bfc-45af-721c-a2a4-183213fd8a33" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019d2bfc-45af-7c6f-bb1f-67ce09937290" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019d2bfc-45af-7c6f-bb1f-67ce09937290_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019d2bfc-45af-7c6f-bb1f-67ce09937290" xlink:to="loc_us-gaap_SegmentDomain_019d2bfc-45af-7c6f-bb1f-67ce09937290_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019d2bfc-45af-7f82-8c4a-12f088640c9a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019d2bfc-45af-7c6f-bb1f-67ce09937290" xlink:to="loc_us-gaap_SegmentDomain_019d2bfc-45af-7f82-8c4a-12f088640c9a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_AssetManagementSegmentMember_019d2bfc-45af-7828-8e73-dd76e5ee3b54" xlink:href="abx-20260331.xsd#abx_AssetManagementSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019d2bfc-45af-7f82-8c4a-12f088640c9a" xlink:to="loc_abx_AssetManagementSegmentMember_019d2bfc-45af-7828-8e73-dd76e5ee3b54" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSolutionsSegmentMember_019d2bfc-45af-7974-85ae-6ab8707e953d" xlink:href="abx-20260331.xsd#abx_LifeSolutionsSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019d2bfc-45af-7f82-8c4a-12f088640c9a" xlink:to="loc_abx_LifeSolutionsSegmentMember_019d2bfc-45af-7974-85ae-6ab8707e953d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_TechnologyServicesSegmentMember_019d2bfc-45af-7759-ac92-6a85e5210f95" xlink:href="abx-20260331.xsd#abx_TechnologyServicesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019d2bfc-45af-7f82-8c4a-12f088640c9a" xlink:to="loc_abx_TechnologyServicesSegmentMember_019d2bfc-45af-7759-ac92-6a85e5210f95" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfRevenue_019d2bfc-45af-7321-a7a5-d4c597d681ff" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019d2bfc-45af-71de-9d7a-5c76c92e32b7" xlink:to="loc_us-gaap_CostOfRevenue_019d2bfc-45af-7321-a7a5-d4c597d681ff" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/SEGMENTREPORTINGReconciliationofNetIncomeDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#SEGMENTREPORTINGReconciliationofNetIncomeDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/SEGMENTREPORTINGReconciliationofNetIncomeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019d2bfc-45af-7109-9ac6-fd69ab618664" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019d2bfc-45af-7672-929b-3bb90b5339a7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019d2bfc-45af-7109-9ac6-fd69ab618664" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019d2bfc-45af-7672-929b-3bb90b5339a7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019d2bfc-45af-762a-861e-f693f3b61cce" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019d2bfc-45af-7672-929b-3bb90b5339a7" xlink:to="loc_srt_ConsolidationItemsAxis_019d2bfc-45af-762a-861e-f693f3b61cce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019d2bfc-45af-762a-861e-f693f3b61cce_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_019d2bfc-45af-762a-861e-f693f3b61cce" xlink:to="loc_srt_ConsolidationItemsDomain_019d2bfc-45af-762a-861e-f693f3b61cce_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019d2bfc-45af-7b6f-b553-9e01b94afd4f" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_019d2bfc-45af-762a-861e-f693f3b61cce" xlink:to="loc_srt_ConsolidationItemsDomain_019d2bfc-45af-7b6f-b553-9e01b94afd4f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019d2bfc-45af-7f26-b35f-7f7e647f5dd0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019d2bfc-45af-7b6f-b553-9e01b94afd4f" xlink:to="loc_us-gaap_OperatingSegmentsMember_019d2bfc-45af-7f26-b35f-7f7e647f5dd0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019d2bfc-45af-7658-9d29-ffa730e27e42" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019d2bfc-45af-7672-929b-3bb90b5339a7" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019d2bfc-45af-7658-9d29-ffa730e27e42" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019d2bfc-45af-7658-9d29-ffa730e27e42_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019d2bfc-45af-7658-9d29-ffa730e27e42" xlink:to="loc_us-gaap_SegmentDomain_019d2bfc-45af-7658-9d29-ffa730e27e42_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019d2bfc-45af-7080-813a-524aeafa351a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019d2bfc-45af-7658-9d29-ffa730e27e42" xlink:to="loc_us-gaap_SegmentDomain_019d2bfc-45af-7080-813a-524aeafa351a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_AssetManagementSegmentMember_019d2bfc-45af-7615-bf97-3301af955bc4" xlink:href="abx-20260331.xsd#abx_AssetManagementSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019d2bfc-45af-7080-813a-524aeafa351a" xlink:to="loc_abx_AssetManagementSegmentMember_019d2bfc-45af-7615-bf97-3301af955bc4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSolutionsSegmentMember_019d2bfc-45af-746f-b461-cfa8616961d0" xlink:href="abx-20260331.xsd#abx_LifeSolutionsSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019d2bfc-45af-7080-813a-524aeafa351a" xlink:to="loc_abx_LifeSolutionsSegmentMember_019d2bfc-45af-746f-b461-cfa8616961d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_TechnologyServicesSegmentMember_019d2bfc-45af-77f0-9425-9aeecaaabe1a" xlink:href="abx-20260331.xsd#abx_TechnologyServicesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019d2bfc-45af-7080-813a-524aeafa351a" xlink:to="loc_abx_TechnologyServicesSegmentMember_019d2bfc-45af-77f0-9425-9aeecaaabe1a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_019d2bfc-45af-72b7-83f9-d9247a5fbaad" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GrossProfit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019d2bfc-45af-7109-9ac6-fd69ab618664" xlink:to="loc_us-gaap_GrossProfit_019d2bfc-45af-72b7-83f9-d9247a5fbaad" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingAndMarketingExpense_019d2bfc-45af-7a17-9f62-0a6b9d8119a4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SellingAndMarketingExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019d2bfc-45af-7109-9ac6-fd69ab618664" xlink:to="loc_us-gaap_SellingAndMarketingExpense_019d2bfc-45af-7a17-9f62-0a6b9d8119a4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_019d2bfc-45af-74ae-854f-c6ae1758ab0c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019d2bfc-45af-7109-9ac6-fd69ab618664" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_019d2bfc-45af-74ae-854f-c6ae1758ab0c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_019d2bfc-45af-7321-af9a-32f20a53e748" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019d2bfc-45af-7109-9ac6-fd69ab618664" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_019d2bfc-45af-7321-af9a-32f20a53e748" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019d2bfc-45af-79f3-a6bb-f5e6bcedcbd6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019d2bfc-45af-7109-9ac6-fd69ab618664" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_019d2bfc-45af-79f3-a6bb-f5e6bcedcbd6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAdjustmentOfWarrants_019d2bfc-45af-79ef-ba9b-0ba57f37ee8b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAdjustmentOfWarrants"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019d2bfc-45af-7109-9ac6-fd69ab618664" xlink:to="loc_us-gaap_FairValueAdjustmentOfWarrants_019d2bfc-45af-79ef-ba9b-0ba57f37ee8b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_019d2bfc-45af-74ff-a61c-8dea421ad1c6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019d2bfc-45af-7109-9ac6-fd69ab618664" xlink:to="loc_us-gaap_InterestExpenseNonoperating_019d2bfc-45af-74ff-a61c-8dea421ad1c6" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeInterest_019d2bfc-45af-7236-903a-5627c233dc8c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentIncomeInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019d2bfc-45af-7109-9ac6-fd69ab618664" xlink:to="loc_us-gaap_InvestmentIncomeInterest_019d2bfc-45af-7236-903a-5627c233dc8c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_019d2bfc-45af-7db5-af31-d2b23c1c4608" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019d2bfc-45af-7109-9ac6-fd69ab618664" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_019d2bfc-45af-7db5-af31-d2b23c1c4608" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss_019d2bfc-45af-7182-9f68-b826ffce2e5b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019d2bfc-45af-7109-9ac6-fd69ab618664" xlink:to="loc_us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss_019d2bfc-45af-7182-9f68-b826ffce2e5b" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019d2bfc-45af-7b2d-971b-7e90810d9f7e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019d2bfc-45af-7109-9ac6-fd69ab618664" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019d2bfc-45af-7b2d-971b-7e90810d9f7e" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019d2bfc-45af-75cf-b719-135576ad539f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019d2bfc-45af-7109-9ac6-fd69ab618664" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019d2bfc-45af-75cf-b719-135576ad539f" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019d2bfc-45af-7f43-9605-3a6e9679899a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019d2bfc-45af-7109-9ac6-fd69ab618664" xlink:to="loc_us-gaap_NetIncomeLoss_019d2bfc-45af-7f43-9605-3a6e9679899a" xlink:type="arc" order="12"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/SEGMENTREPORTINGRevenuebyGeographicLocationDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#SEGMENTREPORTINGRevenuebyGeographicLocationDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/SEGMENTREPORTINGRevenuebyGeographicLocationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019d2bfc-45af-7609-852b-cd4b214d8eba" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019d2bfc-45af-77e0-9abe-6d55e8557614" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019d2bfc-45af-7609-852b-cd4b214d8eba" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019d2bfc-45af-77e0-9abe-6d55e8557614" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019d2bfc-45af-7c6c-a735-73b705a905d9" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019d2bfc-45af-77e0-9abe-6d55e8557614" xlink:to="loc_srt_StatementGeographicalAxis_019d2bfc-45af-7c6c-a735-73b705a905d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019d2bfc-45af-7c6c-a735-73b705a905d9_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_019d2bfc-45af-7c6c-a735-73b705a905d9" xlink:to="loc_srt_SegmentGeographicalDomain_019d2bfc-45af-7c6c-a735-73b705a905d9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019d2bfc-45af-7718-a188-a2febde8c22c" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_019d2bfc-45af-7c6c-a735-73b705a905d9" xlink:to="loc_srt_SegmentGeographicalDomain_019d2bfc-45af-7718-a188-a2febde8c22c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_019d2bfc-45af-7990-a55d-d04905a50f33" xlink:href="https://xbrl.sec.gov/country/2025/country-2025.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019d2bfc-45af-7718-a188-a2febde8c22c" xlink:to="loc_country_US_019d2bfc-45af-7990-a55d-d04905a50f33" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_LU_019d2bfc-45af-7be2-bf8e-900da3f236d4" xlink:href="https://xbrl.sec.gov/country/2025/country-2025.xsd#country_LU"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019d2bfc-45af-7718-a188-a2febde8c22c" xlink:to="loc_country_LU_019d2bfc-45af-7be2-bf8e-900da3f236d4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_OtherGeographicalLocationMember_019d2bfc-45af-723e-bb71-ce443ad5a128" xlink:href="abx-20260331.xsd#abx_OtherGeographicalLocationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019d2bfc-45af-7718-a188-a2febde8c22c" xlink:to="loc_abx_OtherGeographicalLocationMember_019d2bfc-45af-723e-bb71-ce443ad5a128" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019d2bfc-45af-73ad-b433-971de79d1a53" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019d2bfc-45af-7609-852b-cd4b214d8eba" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019d2bfc-45af-73ad-b433-971de79d1a53" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/COMMITMENTSANDCONTINGENCIESDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#COMMITMENTSANDCONTINGENCIESDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/COMMITMENTSANDCONTINGENCIESDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsLineItems_019dd48d-41c9-786f-99b7-b8915c4c452d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCommitmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsTable_019d2bfc-45af-733e-b2b9-3114193cf219" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCommitmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019dd48d-41c9-786f-99b7-b8915c4c452d" xlink:to="loc_us-gaap_OtherCommitmentsTable_019d2bfc-45af-733e-b2b9-3114193cf219" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019dd48d-41c9-76a7-9907-592a00327fa9" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OtherCommitmentsTable_019d2bfc-45af-733e-b2b9-3114193cf219" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019dd48d-41c9-76a7-9907-592a00327fa9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019dd48d-41c9-76a7-9907-592a00327fa9_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019dd48d-41c9-76a7-9907-592a00327fa9" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019dd48d-41c9-76a7-9907-592a00327fa9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019dd48d-41c9-78da-8590-13d825cbb83a" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019dd48d-41c9-76a7-9907-592a00327fa9" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019dd48d-41c9-78da-8590-13d825cbb83a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_ManningNapierMember_019dd48d-41c9-7e58-94db-c47c63337a56" xlink:href="abx-20260331.xsd#abx_ManningNapierMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_019dd48d-41c9-78da-8590-13d825cbb83a" xlink:to="loc_abx_ManningNapierMember_019dd48d-41c9-7e58-94db-c47c63337a56" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireInvestments_019dd48d-41c9-7da2-b479-903829cfaba0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019dd48d-41c9-786f-99b7-b8915c4c452d" xlink:to="loc_us-gaap_PaymentsToAcquireInvestments_019dd48d-41c9-7da2-b479-903829cfaba0" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/FAIRVALUEMEASUREMENTSRecurringFairValueMeasurementsDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#FAIRVALUEMEASUREMENTSRecurringFairValueMeasurementsDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/FAIRVALUEMEASUREMENTSRecurringFairValueMeasurementsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019d2bfc-45af-7106-a25b-aafd360c54d6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019d2bfc-45af-7aad-907b-6dc771d7e0c5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019d2bfc-45af-7106-a25b-aafd360c54d6" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019d2bfc-45af-7aad-907b-6dc771d7e0c5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019d2bfc-45af-7437-a40e-a4fc528a469c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019d2bfc-45af-7aad-907b-6dc771d7e0c5" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019d2bfc-45af-7437-a40e-a4fc528a469c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019d2bfc-45af-7437-a40e-a4fc528a469c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019d2bfc-45af-7437-a40e-a4fc528a469c" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019d2bfc-45af-7437-a40e-a4fc528a469c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019d2bfc-45af-795c-80d0-2ee713797286" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019d2bfc-45af-7437-a40e-a4fc528a469c" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019d2bfc-45af-795c-80d0-2ee713797286" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_019d2bfc-45af-7b73-9008-7edc8d052eb4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019d2bfc-45af-795c-80d0-2ee713797286" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_019d2bfc-45af-7b73-9008-7edc8d052eb4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019d2bfc-45af-7da5-ae34-0db19bccdf25" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019d2bfc-45af-795c-80d0-2ee713797286" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019d2bfc-45af-7da5-ae34-0db19bccdf25" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_019d2bfc-45af-7a0f-95d7-c24283336872" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019d2bfc-45af-795c-80d0-2ee713797286" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_019d2bfc-45af-7a0f-95d7-c24283336872" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosureAbstract_019d2bfc-45af-78da-ae7a-906faf6b23c4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsFairValueDisclosureAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019d2bfc-45af-7106-a25b-aafd360c54d6" xlink:to="loc_us-gaap_AssetsFairValueDisclosureAbstract_019d2bfc-45af-78da-ae7a-906faf6b23c4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LifeSettlementContractsFairValueMethodCarryingAmount_019d2bfc-45af-7e87-ba17-1ccce069c084" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LifeSettlementContractsFairValueMethodCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_019d2bfc-45af-78da-ae7a-906faf6b23c4" xlink:to="loc_us-gaap_LifeSettlementContractsFairValueMethodCarryingAmount_019d2bfc-45af-7e87-ba17-1ccce069c084" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_019d2bfc-45af-725e-bef6-3d887ac8b583" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_019d2bfc-45af-78da-ae7a-906faf6b23c4" xlink:to="loc_us-gaap_AssetsFairValueDisclosure_019d2bfc-45af-725e-bef6-3d887ac8b583" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_019d2bfc-45af-748f-88da-626ad17ef2d9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesFairValueDisclosureAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019d2bfc-45af-7106-a25b-aafd360c54d6" xlink:to="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_019d2bfc-45af-748f-88da-626ad17ef2d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LongTermDebtExcludingCurrentMaturitiesFairValue_019dd48e-1efd-75aa-9477-8ffe4a1b648f" xlink:href="abx-20260331.xsd#abx_LongTermDebtExcludingCurrentMaturitiesFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_019d2bfc-45af-748f-88da-626ad17ef2d9" xlink:to="loc_abx_LongTermDebtExcludingCurrentMaturitiesFairValue_019dd48e-1efd-75aa-9477-8ffe4a1b648f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LongTermDebtCurrentMaturitiesFairValue_019d2bfc-45af-7140-b297-a04da9009120" xlink:href="abx-20260331.xsd#abx_LongTermDebtCurrentMaturitiesFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_019d2bfc-45af-748f-88da-626ad17ef2d9" xlink:to="loc_abx_LongTermDebtCurrentMaturitiesFairValue_019d2bfc-45af-7140-b297-a04da9009120" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosure_019d2bfc-45af-7ea2-9ca9-20beb742007f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_019d2bfc-45af-748f-88da-626ad17ef2d9" xlink:to="loc_us-gaap_LiabilitiesFairValueDisclosure_019d2bfc-45af-7ea2-9ca9-20beb742007f" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/FAIRVALUEMEASUREMENTSSignificantUnobservableInputsDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#FAIRVALUEMEASUREMENTSSignificantUnobservableInputsDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/FAIRVALUEMEASUREMENTSSignificantUnobservableInputsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019d2bfc-45af-7b83-a859-021f2cde0609" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019d2bfc-45af-7ec6-a7de-194e508c07f8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019d2bfc-45af-7b83-a859-021f2cde0609" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019d2bfc-45af-7ec6-a7de-194e508c07f8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019d2bfc-45af-798c-85ed-36e85c341e59" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019d2bfc-45af-7ec6-a7de-194e508c07f8" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019d2bfc-45af-798c-85ed-36e85c341e59" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019d2bfc-45af-798c-85ed-36e85c341e59_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019d2bfc-45af-798c-85ed-36e85c341e59" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019d2bfc-45af-798c-85ed-36e85c341e59_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019d2bfc-45af-7a42-ae55-c761522be3f9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019d2bfc-45af-798c-85ed-36e85c341e59" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019d2bfc-45af-7a42-ae55-c761522be3f9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_019d2bfc-45af-7729-8005-1f7d89fc1210" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019d2bfc-45af-7a42-ae55-c761522be3f9" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_019d2bfc-45af-7729-8005-1f7d89fc1210" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueAxis_019d2bfc-45af-7aff-affc-449bfc89f7a8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019d2bfc-45af-7ec6-a7de-194e508c07f8" xlink:to="loc_us-gaap_ValuationTechniqueAxis_019d2bfc-45af-7aff-affc-449bfc89f7a8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDomain_019d2bfc-45af-7aff-affc-449bfc89f7a8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationTechniqueAxis_019d2bfc-45af-7aff-affc-449bfc89f7a8" xlink:to="loc_us-gaap_ValuationTechniqueDomain_019d2bfc-45af-7aff-affc-449bfc89f7a8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDomain_019d2bfc-45af-7444-ad13-5ff6d6228e93" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationTechniqueAxis_019d2bfc-45af-7aff-affc-449bfc89f7a8" xlink:to="loc_us-gaap_ValuationTechniqueDomain_019d2bfc-45af-7444-ad13-5ff6d6228e93" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDiscountedCashFlowMember_019d2bfc-45af-75c1-9c7a-9513e9bc4d15" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueDiscountedCashFlowMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_019d2bfc-45af-7444-ad13-5ff6d6228e93" xlink:to="loc_us-gaap_ValuationTechniqueDiscountedCashFlowMember_019d2bfc-45af-75c1-9c7a-9513e9bc4d15" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019d2bfc-45af-75f1-8468-c341498984f6" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019d2bfc-45af-7ec6-a7de-194e508c07f8" xlink:to="loc_srt_RangeAxis_019d2bfc-45af-75f1-8468-c341498984f6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019d2bfc-45af-75f1-8468-c341498984f6_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019d2bfc-45af-75f1-8468-c341498984f6" xlink:to="loc_srt_RangeMember_019d2bfc-45af-75f1-8468-c341498984f6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019d2bfc-45af-7fc5-bf21-65b384e01705" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019d2bfc-45af-75f1-8468-c341498984f6" xlink:to="loc_srt_RangeMember_019d2bfc-45af-7fc5-bf21-65b384e01705" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_WeightedAverageMember_019d2bfc-45af-7dd4-be59-29bd5ef6d614" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_WeightedAverageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019d2bfc-45af-7fc5-bf21-65b384e01705" xlink:to="loc_srt_WeightedAverageMember_019d2bfc-45af-7dd4-be59-29bd5ef6d614" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019d2bfc-45af-7c57-a880-300bf4ff8792" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019d2bfc-45af-7fc5-bf21-65b384e01705" xlink:to="loc_srt_MinimumMember_019d2bfc-45af-7c57-a880-300bf4ff8792" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019d2bfc-45af-7a9a-bd98-8495e172a4b1" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019d2bfc-45af-7fc5-bf21-65b384e01705" xlink:to="loc_srt_MaximumMember_019d2bfc-45af-7a9a-bd98-8495e172a4b1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_019d2bfc-45af-78c9-b8f3-7b0fd891d57a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019d2bfc-45af-7ec6-a7de-194e508c07f8" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_019d2bfc-45af-78c9-b8f3-7b0fd891d57a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_019d2bfc-45af-78c9-b8f3-7b0fd891d57a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_019d2bfc-45af-78c9-b8f3-7b0fd891d57a" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_019d2bfc-45af-78c9-b8f3-7b0fd891d57a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_019d2bfc-45af-7039-89fa-87957423c63c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_019d2bfc-45af-78c9-b8f3-7b0fd891d57a" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_019d2bfc-45af-7039-89fa-87957423c63c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputDiscountRateMember_019d2bfc-45af-7906-969c-4d5823cddf7c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputDiscountRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_019d2bfc-45af-7039-89fa-87957423c63c" xlink:to="loc_us-gaap_MeasurementInputDiscountRateMember_019d2bfc-45af-7906-969c-4d5823cddf7c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_MeasurementInputHistoricalRealizedGainsByRiskCategoryMember_019d2bfc-45af-7a55-8d18-6a42275e8618" xlink:href="abx-20260331.xsd#abx_MeasurementInputHistoricalRealizedGainsByRiskCategoryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_019d2bfc-45af-7039-89fa-87957423c63c" xlink:to="loc_abx_MeasurementInputHistoricalRealizedGainsByRiskCategoryMember_019d2bfc-45af-7a55-8d18-6a42275e8618" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_MeasurementInputLifeExpectancyMember_019d2bfc-45af-7d13-9ef6-5af3b18e39fe" xlink:href="abx-20260331.xsd#abx_MeasurementInputLifeExpectancyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_019d2bfc-45af-7039-89fa-87957423c63c" xlink:to="loc_abx_MeasurementInputLifeExpectancyMember_019d2bfc-45af-7d13-9ef6-5af3b18e39fe" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_MeasurementInputRiskScoreMember_019d2bfc-45af-723c-a719-cb962e22ada7" xlink:href="abx-20260331.xsd#abx_MeasurementInputRiskScoreMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_019d2bfc-45af-7039-89fa-87957423c63c" xlink:to="loc_abx_MeasurementInputRiskScoreMember_019d2bfc-45af-723c-a719-cb962e22ada7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LifeSettlementContractsFairValueMethodCarryingAmount_019d2bfc-45af-7e76-80fb-c0400d134019" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LifeSettlementContractsFairValueMethodCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019d2bfc-45af-7b83-a859-021f2cde0609" xlink:to="loc_us-gaap_LifeSettlementContractsFairValueMethodCarryingAmount_019d2bfc-45af-7e76-80fb-c0400d134019" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSettlementContractsMeasurementInput_019d2bfc-45af-75dc-a5d0-f3bca70e1a4f" xlink:href="abx-20260331.xsd#abx_LifeSettlementContractsMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019d2bfc-45af-7b83-a859-021f2cde0609" xlink:to="loc_abx_LifeSettlementContractsMeasurementInput_019d2bfc-45af-75dc-a5d0-f3bca70e1a4f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LongTermDebtExcludingCurrentMaturitiesFairValue_019e02e4-da65-7921-aca8-4435a6ff4ca1" xlink:href="abx-20260331.xsd#abx_LongTermDebtExcludingCurrentMaturitiesFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019d2bfc-45af-7b83-a859-021f2cde0609" xlink:to="loc_abx_LongTermDebtExcludingCurrentMaturitiesFairValue_019e02e4-da65-7921-aca8-4435a6ff4ca1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMeasurementInput_019e02e4-b860-762b-b565-a39237398e8d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019d2bfc-45af-7b83-a859-021f2cde0609" xlink:to="loc_us-gaap_LongTermDebtMeasurementInput_019e02e4-b860-762b-b565-a39237398e8d" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/FAIRVALUEMEASUREMENTSNarrativeDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#FAIRVALUEMEASUREMENTSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/FAIRVALUEMEASUREMENTSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019dd496-4654-709f-8f01-9c1fa27094b8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019d2bfc-45af-79be-92dc-41fc8da794b8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019dd496-4654-709f-8f01-9c1fa27094b8" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019d2bfc-45af-79be-92dc-41fc8da794b8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019dd496-4654-7ba6-a2a2-a9215a96c79c" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019d2bfc-45af-79be-92dc-41fc8da794b8" xlink:to="loc_srt_RangeAxis_019dd496-4654-7ba6-a2a2-a9215a96c79c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019dd496-4654-7ba6-a2a2-a9215a96c79c_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019dd496-4654-7ba6-a2a2-a9215a96c79c" xlink:to="loc_srt_RangeMember_019dd496-4654-7ba6-a2a2-a9215a96c79c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019dd496-4654-7e7c-b4bf-3de9473e5a53" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019dd496-4654-7ba6-a2a2-a9215a96c79c" xlink:to="loc_srt_RangeMember_019dd496-4654-7e7c-b4bf-3de9473e5a53" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_WeightedAverageMember_019dd496-4654-714f-a693-9159fcf0cf12" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_WeightedAverageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019dd496-4654-7e7c-b4bf-3de9473e5a53" xlink:to="loc_srt_WeightedAverageMember_019dd496-4654-714f-a693-9159fcf0cf12" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_019dd496-4654-7016-8249-ede92d3cd8e8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019d2bfc-45af-79be-92dc-41fc8da794b8" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_019dd496-4654-7016-8249-ede92d3cd8e8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_019dd496-4654-7016-8249-ede92d3cd8e8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_019dd496-4654-7016-8249-ede92d3cd8e8" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_019dd496-4654-7016-8249-ede92d3cd8e8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_019dd496-4654-7b91-aa99-29780368c335" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_019dd496-4654-7016-8249-ede92d3cd8e8" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_019dd496-4654-7b91-aa99-29780368c335" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputDiscountRateMember_019dd496-4654-707e-9db1-35289d9f547e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputDiscountRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_019dd496-4654-7b91-aa99-29780368c335" xlink:to="loc_us-gaap_MeasurementInputDiscountRateMember_019dd496-4654-707e-9db1-35289d9f547e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueAxis_019dd496-4654-734b-9d27-0e726c2afe0f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019d2bfc-45af-79be-92dc-41fc8da794b8" xlink:to="loc_us-gaap_ValuationTechniqueAxis_019dd496-4654-734b-9d27-0e726c2afe0f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDomain_019dd496-4654-734b-9d27-0e726c2afe0f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationTechniqueAxis_019dd496-4654-734b-9d27-0e726c2afe0f" xlink:to="loc_us-gaap_ValuationTechniqueDomain_019dd496-4654-734b-9d27-0e726c2afe0f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDomain_019dd496-4654-7ab5-8e5f-4670cb3809b9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationTechniqueAxis_019dd496-4654-734b-9d27-0e726c2afe0f" xlink:to="loc_us-gaap_ValuationTechniqueDomain_019dd496-4654-7ab5-8e5f-4670cb3809b9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDiscountedCashFlowMember_019dd496-4654-7a52-89f9-bfe914ef0e30" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueDiscountedCashFlowMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_019dd496-4654-7ab5-8e5f-4670cb3809b9" xlink:to="loc_us-gaap_ValuationTechniqueDiscountedCashFlowMember_019dd496-4654-7a52-89f9-bfe914ef0e30" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e02e0-4def-7165-8ffd-f98ebfbfef45" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019d2bfc-45af-79be-92dc-41fc8da794b8" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e02e0-4def-7165-8ffd-f98ebfbfef45" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e02e0-4def-7165-8ffd-f98ebfbfef45_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e02e0-4def-7165-8ffd-f98ebfbfef45" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e02e0-4def-7165-8ffd-f98ebfbfef45_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e02e0-4def-752d-b2b9-1d8e275172fa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e02e0-4def-7165-8ffd-f98ebfbfef45" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e02e0-4def-752d-b2b9-1d8e275172fa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_019e02e0-4def-70fe-8fbc-fee609565b8a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e02e0-4def-752d-b2b9-1d8e275172fa" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_019e02e0-4def-70fe-8fbc-fee609565b8a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSettlementContractsMeasurementInput_019dd496-4654-7885-a3a5-04709e910666" xlink:href="abx-20260331.xsd#abx_LifeSettlementContractsMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019dd496-4654-709f-8f01-9c1fa27094b8" xlink:to="loc_abx_LifeSettlementContractsMeasurementInput_019dd496-4654-7885-a3a5-04709e910666" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LifeSettlementContractsInvestmentMethodCarryingAmount_019dd496-4654-74dd-94a4-d53f87667923" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LifeSettlementContractsInvestmentMethodCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019dd496-4654-709f-8f01-9c1fa27094b8" xlink:to="loc_us-gaap_LifeSettlementContractsInvestmentMethodCarryingAmount_019dd496-4654-74dd-94a4-d53f87667923" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019dd496-883a-7456-92a6-c619eff3a571" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019dd496-4654-709f-8f01-9c1fa27094b8" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019dd496-883a-7456-92a6-c619eff3a571" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount_019dd496-883a-7e08-8ac2-041901257400" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019dd496-4654-709f-8f01-9c1fa27094b8" xlink:to="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount_019dd496-883a-7e08-8ac2-041901257400" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/FAIRVALUEMEASUREMENTSRateandSpreadSensitivityDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#FAIRVALUEMEASUREMENTSRateandSpreadSensitivityDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/FAIRVALUEMEASUREMENTSRateandSpreadSensitivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019d2bfc-45af-71ef-ab03-f9d757140600" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019d2bfc-45af-75a3-bc29-e997f3354a1e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019d2bfc-45af-71ef-ab03-f9d757140600" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019d2bfc-45af-75a3-bc29-e997f3354a1e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_019d2bfc-45af-7ce7-b4c8-732c2e2ba6bf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019d2bfc-45af-75a3-bc29-e997f3354a1e" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_019d2bfc-45af-7ce7-b4c8-732c2e2ba6bf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_019d2bfc-45af-7ce7-b4c8-732c2e2ba6bf_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_019d2bfc-45af-7ce7-b4c8-732c2e2ba6bf" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_019d2bfc-45af-7ce7-b4c8-732c2e2ba6bf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_019d2bfc-45af-748d-bd6a-4b753bf21384" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_019d2bfc-45af-7ce7-b4c8-732c2e2ba6bf" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_019d2bfc-45af-748d-bd6a-4b753bf21384" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputDiscountRateMember_019d2bfc-45af-78bf-8d40-154f64d37765" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputDiscountRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_019d2bfc-45af-748d-bd6a-4b753bf21384" xlink:to="loc_us-gaap_MeasurementInputDiscountRateMember_019d2bfc-45af-78bf-8d40-154f64d37765" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_MeasurementInputHistoricalRealizedGainsByRiskCategoryMember_019d2bfc-45af-7266-ae67-d0901cdebecb" xlink:href="abx-20260331.xsd#abx_MeasurementInputHistoricalRealizedGainsByRiskCategoryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_019d2bfc-45af-748d-bd6a-4b753bf21384" xlink:to="loc_abx_MeasurementInputHistoricalRealizedGainsByRiskCategoryMember_019d2bfc-45af-7266-ae67-d0901cdebecb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_SensitivityAnalysisOfFairValueLifeSettlementContractsFairValueImpactOf1PercentPositiveChangeInRate_019d2bfc-45af-779e-8b73-f447735b2d83" xlink:href="abx-20260331.xsd#abx_SensitivityAnalysisOfFairValueLifeSettlementContractsFairValueImpactOf1PercentPositiveChangeInRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019d2bfc-45af-71ef-ab03-f9d757140600" xlink:to="loc_abx_SensitivityAnalysisOfFairValueLifeSettlementContractsFairValueImpactOf1PercentPositiveChangeInRate_019d2bfc-45af-779e-8b73-f447735b2d83" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LifeSettlementContractsFairValueMethodCarryingAmount_019d2bfc-45af-7295-8e58-410751b49c21" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LifeSettlementContractsFairValueMethodCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019d2bfc-45af-71ef-ab03-f9d757140600" xlink:to="loc_us-gaap_LifeSettlementContractsFairValueMethodCarryingAmount_019d2bfc-45af-7295-8e58-410751b49c21" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_SensitivityAnalysisOfFairValueLifeSettlementContractsFairValueImpactOf1PercentAdverseChangeInRate_019d2bfc-45af-7a1f-8b4f-7cc455147747" xlink:href="abx-20260331.xsd#abx_SensitivityAnalysisOfFairValueLifeSettlementContractsFairValueImpactOf1PercentAdverseChangeInRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019d2bfc-45af-71ef-ab03-f9d757140600" xlink:to="loc_abx_SensitivityAnalysisOfFairValueLifeSettlementContractsFairValueImpactOf1PercentAdverseChangeInRate_019d2bfc-45af-7a1f-8b4f-7cc455147747" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_SensitivityAnalysisOfFairValueChangeInLifeSettlementContractsFairValueImpactOf1PercentPositiveChangeInRate_019d2bfc-45af-7251-b51b-3280bb6a1eae" xlink:href="abx-20260331.xsd#abx_SensitivityAnalysisOfFairValueChangeInLifeSettlementContractsFairValueImpactOf1PercentPositiveChangeInRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019d2bfc-45af-71ef-ab03-f9d757140600" xlink:to="loc_abx_SensitivityAnalysisOfFairValueChangeInLifeSettlementContractsFairValueImpactOf1PercentPositiveChangeInRate_019d2bfc-45af-7251-b51b-3280bb6a1eae" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_SensitivityAnalysisOfFairValueChangeInLifeSettlementContractsFairValueImpactOf1PercentAdverseChangeInRate_019d2bfc-45af-7de6-af80-06f67d2ad69d" xlink:href="abx-20260331.xsd#abx_SensitivityAnalysisOfFairValueChangeInLifeSettlementContractsFairValueImpactOf1PercentAdverseChangeInRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019d2bfc-45af-71ef-ab03-f9d757140600" xlink:to="loc_abx_SensitivityAnalysisOfFairValueChangeInLifeSettlementContractsFairValueImpactOf1PercentAdverseChangeInRate_019d2bfc-45af-7de6-af80-06f67d2ad69d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_SensitivityAnalysisOfFairValueLifeSettlementContractsMeasurementInputImpactOf1PercentPositiveChangeInRate_019d2bfc-45af-7a6b-bce3-9a490cf3b20b" xlink:href="abx-20260331.xsd#abx_SensitivityAnalysisOfFairValueLifeSettlementContractsMeasurementInputImpactOf1PercentPositiveChangeInRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019d2bfc-45af-71ef-ab03-f9d757140600" xlink:to="loc_abx_SensitivityAnalysisOfFairValueLifeSettlementContractsMeasurementInputImpactOf1PercentPositiveChangeInRate_019d2bfc-45af-7a6b-bce3-9a490cf3b20b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSettlementContractsMeasurementInput_019d2bfc-45af-7ac8-bb35-482b2618a257" xlink:href="abx-20260331.xsd#abx_LifeSettlementContractsMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019d2bfc-45af-71ef-ab03-f9d757140600" xlink:to="loc_abx_LifeSettlementContractsMeasurementInput_019d2bfc-45af-7ac8-bb35-482b2618a257" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_SensitivityAnalysisOfFairValueLifeSettlementContractsMeasurementInputImpactOf1PercentAdverseChangeInRate_019d2bfc-45af-7025-b519-c35d08e8322e" xlink:href="abx-20260331.xsd#abx_SensitivityAnalysisOfFairValueLifeSettlementContractsMeasurementInputImpactOf1PercentAdverseChangeInRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019d2bfc-45af-71ef-ab03-f9d757140600" xlink:to="loc_abx_SensitivityAnalysisOfFairValueLifeSettlementContractsMeasurementInputImpactOf1PercentAdverseChangeInRate_019d2bfc-45af-7025-b519-c35d08e8322e" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/FAIRVALUEMEASUREMENTSCreditExposuretoInsuranceCompaniesDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#FAIRVALUEMEASUREMENTSCreditExposuretoInsuranceCompaniesDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/FAIRVALUEMEASUREMENTSCreditExposuretoInsuranceCompaniesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueConcentrationOfRiskFinancialStatementCaptionsLineItems_019d2bfc-45af-7f8f-8b9c-151d90a6ce0c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueConcentrationOfRiskFinancialStatementCaptionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueConcentrationOfRiskTable_019d2bfc-45af-7631-84f3-407cc0170adf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueConcentrationOfRiskTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueConcentrationOfRiskFinancialStatementCaptionsLineItems_019d2bfc-45af-7f8f-8b9c-151d90a6ce0c" xlink:to="loc_us-gaap_FairValueConcentrationOfRiskTable_019d2bfc-45af-7631-84f3-407cc0170adf" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_019d2bfc-45af-7df7-8c3e-251ea2f7b703" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueConcentrationOfRiskTable_019d2bfc-45af-7631-84f3-407cc0170adf" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_019d2bfc-45af-7df7-8c3e-251ea2f7b703" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019d2bfc-45af-7df7-8c3e-251ea2f7b703_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019d2bfc-45af-7df7-8c3e-251ea2f7b703" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019d2bfc-45af-7df7-8c3e-251ea2f7b703_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019d2bfc-45af-738e-9fb1-61e1859a1536" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019d2bfc-45af-7df7-8c3e-251ea2f7b703" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019d2bfc-45af-738e-9fb1-61e1859a1536" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeInsuranceCarrierConcentrationRiskMember_019d2bfc-45af-7e6b-924e-7a75792368c2" xlink:href="abx-20260331.xsd#abx_LifeInsuranceCarrierConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_019d2bfc-45af-738e-9fb1-61e1859a1536" xlink:to="loc_abx_LifeInsuranceCarrierConcentrationRiskMember_019d2bfc-45af-7e6b-924e-7a75792368c2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019d2bfc-45af-73d8-91a3-4dec1b4525e2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueConcentrationOfRiskTable_019d2bfc-45af-7631-84f3-407cc0170adf" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019d2bfc-45af-73d8-91a3-4dec1b4525e2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019d2bfc-45af-73d8-91a3-4dec1b4525e2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019d2bfc-45af-73d8-91a3-4dec1b4525e2" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019d2bfc-45af-73d8-91a3-4dec1b4525e2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019d2bfc-45af-72ac-9db4-eb34882803dd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019d2bfc-45af-73d8-91a3-4dec1b4525e2" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019d2bfc-45af-72ac-9db4-eb34882803dd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSettlementContractsFaceValueMember_019d2bfc-45af-71ff-9262-d28d931a2db1" xlink:href="abx-20260331.xsd#abx_LifeSettlementContractsFaceValueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019d2bfc-45af-72ac-9db4-eb34882803dd" xlink:to="loc_abx_LifeSettlementContractsFaceValueMember_019d2bfc-45af-71ff-9262-d28d931a2db1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSettlementContractsFairValueMember_019d2bfc-45af-7e6f-8d39-b51d3fc5cc70" xlink:href="abx-20260331.xsd#abx_LifeSettlementContractsFairValueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019d2bfc-45af-72ac-9db4-eb34882803dd" xlink:to="loc_abx_LifeSettlementContractsFairValueMember_019d2bfc-45af-7e6f-8d39-b51d3fc5cc70" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeInsuranceCarrierAxis_019d2bfc-45af-72a8-a9c3-a73483e0f855" xlink:href="abx-20260331.xsd#abx_LifeInsuranceCarrierAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueConcentrationOfRiskTable_019d2bfc-45af-7631-84f3-407cc0170adf" xlink:to="loc_abx_LifeInsuranceCarrierAxis_019d2bfc-45af-72a8-a9c3-a73483e0f855" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeInsuranceCarrierDomain_019d2bfc-45af-72a8-a9c3-a73483e0f855_default" xlink:href="abx-20260331.xsd#abx_LifeInsuranceCarrierDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_abx_LifeInsuranceCarrierAxis_019d2bfc-45af-72a8-a9c3-a73483e0f855" xlink:to="loc_abx_LifeInsuranceCarrierDomain_019d2bfc-45af-72a8-a9c3-a73483e0f855_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeInsuranceCarrierDomain_019d2bfc-45af-7ad5-b3ef-091d681b344e" xlink:href="abx-20260331.xsd#abx_LifeInsuranceCarrierDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_abx_LifeInsuranceCarrierAxis_019d2bfc-45af-72a8-a9c3-a73483e0f855" xlink:to="loc_abx_LifeInsuranceCarrierDomain_019d2bfc-45af-7ad5-b3ef-091d681b344e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_TransamericaMember_019d2bfc-45af-723d-b7d6-40b58ea723f7" xlink:href="abx-20260331.xsd#abx_TransamericaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_LifeInsuranceCarrierDomain_019d2bfc-45af-7ad5-b3ef-091d681b344e" xlink:to="loc_abx_TransamericaMember_019d2bfc-45af-723d-b7d6-40b58ea723f7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LincolnNationalLifeInsuranceCompanyMember_019d2bfc-45af-72a2-ae03-9c33e5ff83df" xlink:href="abx-20260331.xsd#abx_LincolnNationalLifeInsuranceCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_LifeInsuranceCarrierDomain_019d2bfc-45af-7ad5-b3ef-091d681b344e" xlink:to="loc_abx_LincolnNationalLifeInsuranceCompanyMember_019d2bfc-45af-72a2-ae03-9c33e5ff83df" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_019d2bfc-45af-798b-b511-f19d3b4a132a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueConcentrationOfRiskFinancialStatementCaptionsLineItems_019d2bfc-45af-7f8f-8b9c-151d90a6ce0c" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_019d2bfc-45af-798b-b511-f19d3b4a132a" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/FAIRVALUEMEASUREMENTSLifeInsurancePoliciesDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#FAIRVALUEMEASUREMENTSLifeInsurancePoliciesDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/FAIRVALUEMEASUREMENTSLifeInsurancePoliciesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_019d2bfc-45af-75bd-8c50-1035699c6122" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable_019d2bfc-45af-7ca1-b7a5-932f6a7385cc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_019d2bfc-45af-75bd-8c50-1035699c6122" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable_019d2bfc-45af-7ca1-b7a5-932f6a7385cc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_019d2bfc-45af-72b1-a509-1a4fb6ef0a34" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByAssetClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable_019d2bfc-45af-7ca1-b7a5-932f6a7385cc" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_019d2bfc-45af-72b1-a509-1a4fb6ef0a34" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019d2bfc-45af-72b1-a509-1a4fb6ef0a34_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_019d2bfc-45af-72b1-a509-1a4fb6ef0a34" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019d2bfc-45af-72b1-a509-1a4fb6ef0a34_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019d2bfc-45af-7f19-8794-94a34a680c82" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_019d2bfc-45af-72b1-a509-1a4fb6ef0a34" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019d2bfc-45af-7f19-8794-94a34a680c82" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSettlementContractMember_019d2bfc-45af-7631-9458-e555195b1c95" xlink:href="abx-20260331.xsd#abx_LifeSettlementContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019d2bfc-45af-7f19-8794-94a34a680c82" xlink:to="loc_abx_LifeSettlementContractMember_019d2bfc-45af-7631-9458-e555195b1c95" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_019d2bfc-45af-7979-ad1f-2c4ac566f26d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_019d2bfc-45af-75bd-8c50-1035699c6122" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_019d2bfc-45af-7979-ad1f-2c4ac566f26d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_019d2bfc-45af-73d1-8d1b-805092b4127b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_019d2bfc-45af-7979-ad1f-2c4ac566f26d" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_019d2bfc-45af-73d1-8d1b-805092b4127b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases_019d2bfc-45af-78bf-9059-796570806b06" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_019d2bfc-45af-7979-ad1f-2c4ac566f26d" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases_019d2bfc-45af-78bf-9059-796570806b06" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales_019d2bfc-45af-7cea-ba40-6c4b87c35123" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_019d2bfc-45af-7979-ad1f-2c4ac566f26d" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales_019d2bfc-45af-7cea-ba40-6c4b87c35123" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetUnrealizedGainLossIncludedInEarnings_019d2bfc-45af-7e37-b9cf-f08eb6f9fdd8" xlink:href="abx-20260331.xsd#abx_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetUnrealizedGainLossIncludedInEarnings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_019d2bfc-45af-7979-ad1f-2c4ac566f26d" xlink:to="loc_abx_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetUnrealizedGainLossIncludedInEarnings_019d2bfc-45af-7e37-b9cf-f08eb6f9fdd8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_019d2bfc-45af-778e-9cc7-3ff4f1f7c12b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetRealizedGainLossIncludedInEarnings_019d2bfc-45af-7594-90cf-320a7478cdeb" xlink:href="abx-20260331.xsd#abx_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetRealizedGainLossIncludedInEarnings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_019d2bfc-45af-75bd-8c50-1035699c6122" xlink:to="loc_abx_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetRealizedGainLossIncludedInEarnings_019d2bfc-45af-7594-90cf-320a7478cdeb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPremiumsPaid_019d2bfc-45af-7e89-aef3-002e176a6c77" xlink:href="abx-20260331.xsd#abx_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPremiumsPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_019d2bfc-45af-75bd-8c50-1035699c6122" xlink:to="loc_abx_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPremiumsPaid_019d2bfc-45af-7e89-aef3-002e176a6c77" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetUnrealizedGainLossIncludedInEarnings_019d2bfc-45af-78ae-bc12-11dd9c7f01a0" xlink:href="abx-20260331.xsd#abx_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetUnrealizedGainLossIncludedInEarnings"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1_019d2bfc-45af-7d61-b539-027d2f0ebb00" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_019d2bfc-45af-75bd-8c50-1035699c6122" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1_019d2bfc-45af-7d61-b539-027d2f0ebb00" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/LONGTERMDEBTLongTermDebtDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#LONGTERMDEBTLongTermDebtDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/LONGTERMDEBTLongTermDebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-45af-7606-ab74-a5b9955944fa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019d2bfc-45af-76ac-bfa3-8126798ebaaa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-45af-7606-ab74-a5b9955944fa" xlink:to="loc_us-gaap_DebtInstrumentTable_019d2bfc-45af-76ac-bfa3-8126798ebaaa" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019d2bfc-45af-70f1-ab0b-c267571d0a79" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019d2bfc-45af-76ac-bfa3-8126798ebaaa" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019d2bfc-45af-70f1-ab0b-c267571d0a79" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019d2bfc-45af-70f1-ab0b-c267571d0a79_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019d2bfc-45af-70f1-ab0b-c267571d0a79" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019d2bfc-45af-70f1-ab0b-c267571d0a79_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019d2bfc-45af-74b8-926c-19348450e5da" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019d2bfc-45af-70f1-ab0b-c267571d0a79" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019d2bfc-45af-74b8-926c-19348450e5da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesPayableOtherPayablesMember_019d2bfc-45af-70ac-ac4d-0ed2742a0042" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableOtherPayablesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019d2bfc-45af-74b8-926c-19348450e5da" xlink:to="loc_us-gaap_NotesPayableOtherPayablesMember_019d2bfc-45af-70ac-ac4d-0ed2742a0042" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_019d2bfc-45af-76e6-a815-f91e0b7517cb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019d2bfc-45af-74b8-926c-19348450e5da" xlink:to="loc_us-gaap_SecuredDebtMember_019d2bfc-45af-76e6-a815-f91e0b7517cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnsecuredDebtMember_019d2bfc-45af-7c4c-a068-9a8df86be0f6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnsecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019d2bfc-45af-74b8-926c-19348450e5da" xlink:to="loc_us-gaap_UnsecuredDebtMember_019d2bfc-45af-7c4c-a068-9a8df86be0f6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019d2bfc-45af-727b-ba43-16c1cf66b878" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019d2bfc-45af-76ac-bfa3-8126798ebaaa" xlink:to="loc_us-gaap_DebtInstrumentAxis_019d2bfc-45af-727b-ba43-16c1cf66b878" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-45af-727b-ba43-16c1cf66b878_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019d2bfc-45af-727b-ba43-16c1cf66b878" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-45af-727b-ba43-16c1cf66b878_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-45af-7b00-a9f7-72e736b79a52" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019d2bfc-45af-727b-ba43-16c1cf66b878" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-45af-7b00-a9f7-72e736b79a52" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_SeniorSecuredCreditFacilityMember_019d2bfc-45af-7f93-ba94-78b1d79fe168" xlink:href="abx-20260331.xsd#abx_SeniorSecuredCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-45af-7b00-a9f7-72e736b79a52" xlink:to="loc_abx_SeniorSecuredCreditFacilityMember_019d2bfc-45af-7f93-ba94-78b1d79fe168" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LMAIncomeSeriesIILPMember_019d2bfc-45af-7b69-8ae8-1d1e7f9fe43f" xlink:href="abx-20260331.xsd#abx_LMAIncomeSeriesIILPMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-45af-7b00-a9f7-72e736b79a52" xlink:to="loc_abx_LMAIncomeSeriesIILPMember_019d2bfc-45af-7b69-8ae8-1d1e7f9fe43f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_FixedUnsecuredNotesMember_019d2bfc-45af-7c3c-99f5-9b3c2e728b14" xlink:href="abx-20260331.xsd#abx_FixedUnsecuredNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-45af-7b00-a9f7-72e736b79a52" xlink:to="loc_abx_FixedUnsecuredNotesMember_019d2bfc-45af-7c3c-99f5-9b3c2e728b14" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_SponsorPIKNoteMember_019d2bfc-45af-7ef2-a3f7-4c49def0f340" xlink:href="abx-20260331.xsd#abx_SponsorPIKNoteMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-45af-7b00-a9f7-72e736b79a52" xlink:to="loc_abx_SponsorPIKNoteMember_019d2bfc-45af-7ef2-a3f7-4c49def0f340" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_019d2bfc-45af-7340-8253-374f06a001e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-45af-7606-ab74-a5b9955944fa" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_019d2bfc-45af-7340-8253-374f06a001e7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_019d2bfc-45af-7ea2-8cc5-509adf48f7ca" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-45af-7606-ab74-a5b9955944fa" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_019d2bfc-45af-7ea2-8cc5-509adf48f7ca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_019d2bfc-45af-7717-a30c-a2e7b96f71be" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-45af-7606-ab74-a5b9955944fa" xlink:to="loc_us-gaap_LongTermDebt_019d2bfc-45af-7717-a30c-a2e7b96f71be" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_019d2bfc-45af-715e-a6c7-b8813927cb27" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-45af-7606-ab74-a5b9955944fa" xlink:to="loc_us-gaap_LongTermDebtCurrent_019d2bfc-45af-715e-a6c7-b8813927cb27" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_019d2bfc-45af-7471-990d-73876a2778ef" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-45af-7606-ab74-a5b9955944fa" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_019d2bfc-45af-7471-990d-73876a2778ef" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/LONGTERMDEBTFixedRateSeniorUnsecuredNotesDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#LONGTERMDEBTFixedRateSeniorUnsecuredNotesDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/LONGTERMDEBTFixedRateSeniorUnsecuredNotesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019dfd30-3ed0-7b53-b0b8-fff1425c47a3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019d2bfc-45af-7adc-9d53-6bfff9278938" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019dfd30-3ed0-7b53-b0b8-fff1425c47a3" xlink:to="loc_us-gaap_DebtInstrumentTable_019d2bfc-45af-7adc-9d53-6bfff9278938" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019dfd30-3ed0-7e39-9191-0d3b245d2eb0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019d2bfc-45af-7adc-9d53-6bfff9278938" xlink:to="loc_us-gaap_DebtInstrumentAxis_019dfd30-3ed0-7e39-9191-0d3b245d2eb0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019dfd30-3ed0-7e39-9191-0d3b245d2eb0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019dfd30-3ed0-7e39-9191-0d3b245d2eb0" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019dfd30-3ed0-7e39-9191-0d3b245d2eb0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019dfd30-3ed0-7894-b4bb-a566d4e83860" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019dfd30-3ed0-7e39-9191-0d3b245d2eb0" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019dfd30-3ed0-7894-b4bb-a566d4e83860" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_FixedUnsecuredNotesMember_019dfd30-3ed0-7866-9ba1-2905cb7a605d" xlink:href="abx-20260331.xsd#abx_FixedUnsecuredNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019dfd30-3ed0-7894-b4bb-a566d4e83860" xlink:to="loc_abx_FixedUnsecuredNotesMember_019dfd30-3ed0-7866-9ba1-2905cb7a605d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019dfd30-3ed0-73b8-bffc-ca1b76f5e481" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019d2bfc-45af-7adc-9d53-6bfff9278938" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019dfd30-3ed0-73b8-bffc-ca1b76f5e481" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019dfd30-3ed0-73b8-bffc-ca1b76f5e481_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019dfd30-3ed0-73b8-bffc-ca1b76f5e481" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019dfd30-3ed0-73b8-bffc-ca1b76f5e481_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019dfd30-3ed0-728c-9bb1-cc7ae3892ad9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019dfd30-3ed0-73b8-bffc-ca1b76f5e481" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019dfd30-3ed0-728c-9bb1-cc7ae3892ad9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnsecuredDebtMember_019dfd30-3ed0-70a4-b375-09f566852fd0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnsecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019dfd30-3ed0-728c-9bb1-cc7ae3892ad9" xlink:to="loc_us-gaap_UnsecuredDebtMember_019dfd30-3ed0-70a4-b375-09f566852fd0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019dfd30-3ed0-7904-81a3-d486cb0e4bd6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019dfd30-3ed0-7b53-b0b8-fff1425c47a3" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019dfd30-3ed0-7904-81a3-d486cb0e4bd6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_019dfda6-639b-779b-8b74-4260b3403222" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentRedemptionPricePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019dfd30-3ed0-7b53-b0b8-fff1425c47a3" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_019dfda6-639b-779b-8b74-4260b3403222" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_019dfd30-3ed0-7cec-abd1-1330f179513f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019dfd30-3ed0-7b53-b0b8-fff1425c47a3" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_019dfd30-3ed0-7cec-abd1-1330f179513f" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/LONGTERMDEBTSeniorSecuredCreditFacilityDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#LONGTERMDEBTSeniorSecuredCreditFacilityDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/LONGTERMDEBTSeniorSecuredCreditFacilityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-45af-7688-9a78-9c14e85ccc0b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019d2bfc-45af-7786-b779-9da5655d9d94" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-45af-7688-9a78-9c14e85ccc0b" xlink:to="loc_us-gaap_DebtInstrumentTable_019d2bfc-45af-7786-b779-9da5655d9d94" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019d2bfc-45af-79ee-9c5d-cb3667d5946b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019d2bfc-45af-7786-b779-9da5655d9d94" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019d2bfc-45af-79ee-9c5d-cb3667d5946b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019d2bfc-45af-79ee-9c5d-cb3667d5946b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019d2bfc-45af-79ee-9c5d-cb3667d5946b" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019d2bfc-45af-79ee-9c5d-cb3667d5946b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019d2bfc-45af-705a-be69-0bbde5cfd99b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019d2bfc-45af-79ee-9c5d-cb3667d5946b" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019d2bfc-45af-705a-be69-0bbde5cfd99b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_019d2bfc-45af-7c4f-a71e-ea6ed7c5bfed" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019d2bfc-45af-705a-be69-0bbde5cfd99b" xlink:to="loc_us-gaap_LineOfCreditMember_019d2bfc-45af-7c4f-a71e-ea6ed7c5bfed" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019d2bfc-45af-7382-8257-b3574a17f381" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019d2bfc-45af-7786-b779-9da5655d9d94" xlink:to="loc_us-gaap_CreditFacilityAxis_019d2bfc-45af-7382-8257-b3574a17f381" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019d2bfc-45af-7382-8257-b3574a17f381_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019d2bfc-45af-7382-8257-b3574a17f381" xlink:to="loc_us-gaap_CreditFacilityDomain_019d2bfc-45af-7382-8257-b3574a17f381_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019d2bfc-45af-7924-84a1-62b6d1bcb159" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019d2bfc-45af-7382-8257-b3574a17f381" xlink:to="loc_us-gaap_CreditFacilityDomain_019d2bfc-45af-7924-84a1-62b6d1bcb159" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_019d2bfc-45af-7fc8-a213-e6236c4707ac" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019d2bfc-45af-7924-84a1-62b6d1bcb159" xlink:to="loc_us-gaap_SecuredDebtMember_019d2bfc-45af-7fc8-a213-e6236c4707ac" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DelayedDrawTermLoanMember_019d2bfc-45af-71f4-8b62-8aaaa7c59e94" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DelayedDrawTermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019d2bfc-45af-7924-84a1-62b6d1bcb159" xlink:to="loc_us-gaap_DelayedDrawTermLoanMember_019d2bfc-45af-71f4-8b62-8aaaa7c59e94" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019d2bfc-45af-7810-88f4-02542c1e3013" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019d2bfc-45af-7786-b779-9da5655d9d94" xlink:to="loc_us-gaap_DebtInstrumentAxis_019d2bfc-45af-7810-88f4-02542c1e3013" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-45af-7810-88f4-02542c1e3013_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019d2bfc-45af-7810-88f4-02542c1e3013" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-45af-7810-88f4-02542c1e3013_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-45af-78e8-a43a-7a1e59a2f780" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019d2bfc-45af-7810-88f4-02542c1e3013" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-45af-78e8-a43a-7a1e59a2f780" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_SeniorSecuredCreditFacilityMember_019d2bfc-45af-74fd-a22f-efbf815e46b6" xlink:href="abx-20260331.xsd#abx_SeniorSecuredCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-45af-78e8-a43a-7a1e59a2f780" xlink:to="loc_abx_SeniorSecuredCreditFacilityMember_019d2bfc-45af-74fd-a22f-efbf815e46b6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_DDTLFacilityMember_019d2bfc-45af-74e4-9caf-b4f082be746d" xlink:href="abx-20260331.xsd#abx_DDTLFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-45af-78e8-a43a-7a1e59a2f780" xlink:to="loc_abx_DDTLFacilityMember_019d2bfc-45af-74e4-9caf-b4f082be746d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_019d2bfc-45af-7a74-927e-abd815b367ea" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-45af-7688-9a78-9c14e85ccc0b" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_019d2bfc-45af-7a74-927e-abd815b367ea" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019d2bfc-45af-7cc3-944d-7f21c177c3a0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-45af-7688-9a78-9c14e85ccc0b" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019d2bfc-45af-7cc3-944d-7f21c177c3a0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LineOfCreditFacilityRemainingBorrowingCapacityTerm_019d2bfc-45af-746d-bb73-c858e01747f5" xlink:href="abx-20260331.xsd#abx_LineOfCreditFacilityRemainingBorrowingCapacityTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-45af-7688-9a78-9c14e85ccc0b" xlink:to="loc_abx_LineOfCreditFacilityRemainingBorrowingCapacityTerm_019d2bfc-45af-746d-bb73-c858e01747f5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019d2bfc-45af-7abe-a2e7-1474aa6956bc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-45af-7688-9a78-9c14e85ccc0b" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019d2bfc-45af-7abe-a2e7-1474aa6956bc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019d2bfc-45af-7c4e-9559-1a9a1f7be5dc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-45af-7688-9a78-9c14e85ccc0b" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019d2bfc-45af-7c4e-9559-1a9a1f7be5dc" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_DebtInstrumentBasisSpreadOnVariableRateStepdown_019d2bfc-45af-7035-a813-070514da8dfe" xlink:href="abx-20260331.xsd#abx_DebtInstrumentBasisSpreadOnVariableRateStepdown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-45af-7688-9a78-9c14e85ccc0b" xlink:to="loc_abx_DebtInstrumentBasisSpreadOnVariableRateStepdown_019d2bfc-45af-7035-a813-070514da8dfe" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_DebtInstrumentMinimumPrepayment_019d2bfc-45af-79e7-91ce-ab48cd26aa6d" xlink:href="abx-20260331.xsd#abx_DebtInstrumentMinimumPrepayment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-45af-7688-9a78-9c14e85ccc0b" xlink:to="loc_abx_DebtInstrumentMinimumPrepayment_019d2bfc-45af-79e7-91ce-ab48cd26aa6d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_DebtInstrumentPrepaymentPremiumPercentage_019d2bfc-45af-73cf-9fb3-96b6f28eccea" xlink:href="abx-20260331.xsd#abx_DebtInstrumentPrepaymentPremiumPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-45af-7688-9a78-9c14e85ccc0b" xlink:to="loc_abx_DebtInstrumentPrepaymentPremiumPercentage_019d2bfc-45af-73cf-9fb3-96b6f28eccea" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_DebtInstrumentPrepaymentTermSubjectToPremium_019d2bfc-45af-76d6-8c1b-8d9f68f906b8" xlink:href="abx-20260331.xsd#abx_DebtInstrumentPrepaymentTermSubjectToPremium"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-45af-7688-9a78-9c14e85ccc0b" xlink:to="loc_abx_DebtInstrumentPrepaymentTermSubjectToPremium_019d2bfc-45af-76d6-8c1b-8d9f68f906b8" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/LONGTERMDEBTLMAIncomeSeriesIILPandLMAIncomeSeriesIIGPLLCSecuredBorrowingDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#LONGTERMDEBTLMAIncomeSeriesIILPandLMAIncomeSeriesIIGPLLCSecuredBorrowingDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/LONGTERMDEBTLMAIncomeSeriesIILPandLMAIncomeSeriesIIGPLLCSecuredBorrowingDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b12-abc5-5951f10e80cb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019d2bfc-4668-7922-9cc8-aab10040b118" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b12-abc5-5951f10e80cb" xlink:to="loc_us-gaap_DebtInstrumentTable_019d2bfc-4668-7922-9cc8-aab10040b118" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019d2bfc-4668-760a-a6ed-3946e9cc95d2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019d2bfc-4668-7922-9cc8-aab10040b118" xlink:to="loc_us-gaap_DebtInstrumentAxis_019d2bfc-4668-760a-a6ed-3946e9cc95d2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-4668-760a-a6ed-3946e9cc95d2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019d2bfc-4668-760a-a6ed-3946e9cc95d2" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-4668-760a-a6ed-3946e9cc95d2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-4668-7651-abb7-0dbd8ebd9a18" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019d2bfc-4668-760a-a6ed-3946e9cc95d2" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-4668-7651-abb7-0dbd8ebd9a18" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LMAIncomeSeriesIILPMember_019d2bfc-4668-7e4f-83b6-29dfe59d8ba3" xlink:href="abx-20260331.xsd#abx_LMAIncomeSeriesIILPMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-4668-7651-abb7-0dbd8ebd9a18" xlink:to="loc_abx_LMAIncomeSeriesIILPMember_019d2bfc-4668-7e4f-83b6-29dfe59d8ba3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019d2bfc-4668-7563-b057-01a67b81e4c9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019d2bfc-4668-7922-9cc8-aab10040b118" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019d2bfc-4668-7563-b057-01a67b81e4c9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019d2bfc-4668-7563-b057-01a67b81e4c9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019d2bfc-4668-7563-b057-01a67b81e4c9" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019d2bfc-4668-7563-b057-01a67b81e4c9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019d2bfc-4668-799d-bad0-8148f11628f0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019d2bfc-4668-7563-b057-01a67b81e4c9" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019d2bfc-4668-799d-bad0-8148f11628f0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_019d2bfc-4668-71a2-a406-95c3f4f609ee" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019d2bfc-4668-799d-bad0-8148f11628f0" xlink:to="loc_us-gaap_SecuredDebtMember_019d2bfc-4668-71a2-a406-95c3f4f609ee" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_DebtInstrumentPrivatePlacementOfferingCapitalCommitmentThresholdsAxis_019d2bfc-4668-734f-a131-b642352e8f07" xlink:href="abx-20260331.xsd#abx_DebtInstrumentPrivatePlacementOfferingCapitalCommitmentThresholdsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019d2bfc-4668-7922-9cc8-aab10040b118" xlink:to="loc_abx_DebtInstrumentPrivatePlacementOfferingCapitalCommitmentThresholdsAxis_019d2bfc-4668-734f-a131-b642352e8f07" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_DebtInstrumentPrivatePlacementOfferingCapitalCommitmentThresholdsDomain_019d2bfc-4668-734f-a131-b642352e8f07_default" xlink:href="abx-20260331.xsd#abx_DebtInstrumentPrivatePlacementOfferingCapitalCommitmentThresholdsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_abx_DebtInstrumentPrivatePlacementOfferingCapitalCommitmentThresholdsAxis_019d2bfc-4668-734f-a131-b642352e8f07" xlink:to="loc_abx_DebtInstrumentPrivatePlacementOfferingCapitalCommitmentThresholdsDomain_019d2bfc-4668-734f-a131-b642352e8f07_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_DebtInstrumentPrivatePlacementOfferingCapitalCommitmentThresholdsDomain_019d2bfc-4668-70d9-a1e3-50d10dd8b2a5" xlink:href="abx-20260331.xsd#abx_DebtInstrumentPrivatePlacementOfferingCapitalCommitmentThresholdsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_abx_DebtInstrumentPrivatePlacementOfferingCapitalCommitmentThresholdsAxis_019d2bfc-4668-734f-a131-b642352e8f07" xlink:to="loc_abx_DebtInstrumentPrivatePlacementOfferingCapitalCommitmentThresholdsDomain_019d2bfc-4668-70d9-a1e3-50d10dd8b2a5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_CapitalCommitmentThresholdOneMember_019d2bfc-4668-7de4-aca3-c6dfc6364030" xlink:href="abx-20260331.xsd#abx_CapitalCommitmentThresholdOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_DebtInstrumentPrivatePlacementOfferingCapitalCommitmentThresholdsDomain_019d2bfc-4668-70d9-a1e3-50d10dd8b2a5" xlink:to="loc_abx_CapitalCommitmentThresholdOneMember_019d2bfc-4668-7de4-aca3-c6dfc6364030" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_CapitalCommitmentThresholdTwoMember_019d2bfc-4668-797e-a1b4-0db6594fd76e" xlink:href="abx-20260331.xsd#abx_CapitalCommitmentThresholdTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_DebtInstrumentPrivatePlacementOfferingCapitalCommitmentThresholdsDomain_019d2bfc-4668-70d9-a1e3-50d10dd8b2a5" xlink:to="loc_abx_CapitalCommitmentThresholdTwoMember_019d2bfc-4668-797e-a1b4-0db6594fd76e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_CapitalCommitmentThresholdThreeMember_019d2bfc-4668-7e7f-958c-1d87cf02f747" xlink:href="abx-20260331.xsd#abx_CapitalCommitmentThresholdThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_abx_DebtInstrumentPrivatePlacementOfferingCapitalCommitmentThresholdsDomain_019d2bfc-4668-70d9-a1e3-50d10dd8b2a5" xlink:to="loc_abx_CapitalCommitmentThresholdThreeMember_019d2bfc-4668-7e7f-958c-1d87cf02f747" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PartnerTypeOfPartnersCapitalAccountAxis_019d2bfc-4668-71db-93de-8a2c06924c95" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PartnerTypeOfPartnersCapitalAccountAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019d2bfc-4668-7922-9cc8-aab10040b118" xlink:to="loc_us-gaap_PartnerTypeOfPartnersCapitalAccountAxis_019d2bfc-4668-71db-93de-8a2c06924c95" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PartnerTypeOfPartnersCapitalAccountNameDomain_019d2bfc-4668-71db-93de-8a2c06924c95_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PartnerTypeOfPartnersCapitalAccountNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PartnerTypeOfPartnersCapitalAccountAxis_019d2bfc-4668-71db-93de-8a2c06924c95" xlink:to="loc_us-gaap_PartnerTypeOfPartnersCapitalAccountNameDomain_019d2bfc-4668-71db-93de-8a2c06924c95_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PartnerTypeOfPartnersCapitalAccountNameDomain_019d2bfc-4668-7b0a-86c4-ebf2256f22bd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PartnerTypeOfPartnersCapitalAccountNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PartnerTypeOfPartnersCapitalAccountAxis_019d2bfc-4668-71db-93de-8a2c06924c95" xlink:to="loc_us-gaap_PartnerTypeOfPartnersCapitalAccountNameDomain_019d2bfc-4668-7b0a-86c4-ebf2256f22bd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LimitedPartnerMember_019d2bfc-4668-7dba-a23b-e875f8393a82" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LimitedPartnerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PartnerTypeOfPartnersCapitalAccountNameDomain_019d2bfc-4668-7b0a-86c4-ebf2256f22bd" xlink:to="loc_us-gaap_LimitedPartnerMember_019d2bfc-4668-7dba-a23b-e875f8393a82" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralPartnerMember_019d2bfc-4668-799b-8739-f76a9fb58687" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralPartnerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PartnerTypeOfPartnersCapitalAccountNameDomain_019d2bfc-4668-7b0a-86c4-ebf2256f22bd" xlink:to="loc_us-gaap_GeneralPartnerMember_019d2bfc-4668-799b-8739-f76a9fb58687" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019d2bfc-4668-7166-8275-b273209df5dd" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019d2bfc-4668-7922-9cc8-aab10040b118" xlink:to="loc_srt_RangeAxis_019d2bfc-4668-7166-8275-b273209df5dd" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019d2bfc-4668-7166-8275-b273209df5dd_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019d2bfc-4668-7166-8275-b273209df5dd" xlink:to="loc_srt_RangeMember_019d2bfc-4668-7166-8275-b273209df5dd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019d2bfc-4668-7f8f-8aa8-e9254ee98021" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019d2bfc-4668-7166-8275-b273209df5dd" xlink:to="loc_srt_RangeMember_019d2bfc-4668-7f8f-8aa8-e9254ee98021" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019d2bfc-4668-78a5-b402-c33ec5901d5a" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019d2bfc-4668-7f8f-8aa8-e9254ee98021" xlink:to="loc_srt_MaximumMember_019d2bfc-4668-78a5-b402-c33ec5901d5a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019d2bfc-4668-7ce3-8e6d-145bab97ba4b" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019d2bfc-4668-7f8f-8aa8-e9254ee98021" xlink:to="loc_srt_MinimumMember_019d2bfc-4668-7ce3-8e6d-145bab97ba4b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PledgedStatusAxis_019d2bfc-4668-7fc1-a851-031fa8d201fa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PledgedStatusAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019d2bfc-4668-7922-9cc8-aab10040b118" xlink:to="loc_us-gaap_PledgedStatusAxis_019d2bfc-4668-7fc1-a851-031fa8d201fa" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PledgedStatusDomain_019d2bfc-4668-7fc1-a851-031fa8d201fa_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PledgedStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PledgedStatusAxis_019d2bfc-4668-7fc1-a851-031fa8d201fa" xlink:to="loc_us-gaap_PledgedStatusDomain_019d2bfc-4668-7fc1-a851-031fa8d201fa_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PledgedStatusDomain_019d2bfc-4668-705f-aa20-46e3f39dd713" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PledgedStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PledgedStatusAxis_019d2bfc-4668-7fc1-a851-031fa8d201fa" xlink:to="loc_us-gaap_PledgedStatusDomain_019d2bfc-4668-705f-aa20-46e3f39dd713" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetPledgedAsCollateralMember_019d2bfc-4668-7465-8624-9659b0e7e84c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetPledgedAsCollateralMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PledgedStatusDomain_019d2bfc-4668-705f-aa20-46e3f39dd713" xlink:to="loc_us-gaap_AssetPledgedAsCollateralMember_019d2bfc-4668-7465-8624-9659b0e7e84c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTerm_019d2bfc-4668-7d27-af3b-267386429086" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b12-abc5-5951f10e80cb" xlink:to="loc_us-gaap_DebtInstrumentTerm_019d2bfc-4668-7d27-af3b-267386429086" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_DebtInstrumentExtensionOptions_019d2bfc-4668-737c-890f-e7796e998643" xlink:href="abx-20260331.xsd#abx_DebtInstrumentExtensionOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b12-abc5-5951f10e80cb" xlink:to="loc_abx_DebtInstrumentExtensionOptions_019d2bfc-4668-737c-890f-e7796e998643" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_DebtInstrumentExtensionTerm_019d2bfc-4668-7b0b-855f-30d3476e8e97" xlink:href="abx-20260331.xsd#abx_DebtInstrumentExtensionTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b12-abc5-5951f10e80cb" xlink:to="loc_abx_DebtInstrumentExtensionTerm_019d2bfc-4668-7b0b-855f-30d3476e8e97" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_DebtInstrumentCapitalCommitmentThresholdsToDetermineDividends_019d2bfc-4668-71b7-8ef2-cbbbe496c856" xlink:href="abx-20260331.xsd#abx_DebtInstrumentCapitalCommitmentThresholdsToDetermineDividends"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b12-abc5-5951f10e80cb" xlink:to="loc_abx_DebtInstrumentCapitalCommitmentThresholdsToDetermineDividends_019d2bfc-4668-71b7-8ef2-cbbbe496c856" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_DebtInstrumentDividendFeaturePercentage_019d2bfc-4668-7d36-a047-44c4bfd75179" xlink:href="abx-20260331.xsd#abx_DebtInstrumentDividendFeaturePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b12-abc5-5951f10e80cb" xlink:to="loc_abx_DebtInstrumentDividendFeaturePercentage_019d2bfc-4668-7d36-a047-44c4bfd75179" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_019d2bfc-4668-7924-94cd-e0d46196877d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfLongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b12-abc5-5951f10e80cb" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_019d2bfc-4668-7924-94cd-e0d46196877d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfLongTermDebt_019d2bfc-4668-792d-8ada-85b86955aab4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RepaymentsOfLongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b12-abc5-5951f10e80cb" xlink:to="loc_us-gaap_RepaymentsOfLongTermDebt_019d2bfc-4668-792d-8ada-85b86955aab4" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_019d2bfc-4668-7765-92bc-a9a0707d71c6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b12-abc5-5951f10e80cb" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_019d2bfc-4668-7765-92bc-a9a0707d71c6" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilities_019e02ed-a825-7547-a2c1-962f4eae4233" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b12-abc5-5951f10e80cb" xlink:to="loc_us-gaap_OtherLiabilities_019e02ed-a825-7547-a2c1-962f4eae4233" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019e02ea-ca7e-7bbb-add0-1e961ceee3d9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b12-abc5-5951f10e80cb" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019e02ea-ca7e-7bbb-add0-1e961ceee3d9" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_019e02eb-cfc2-7aaf-9a08-743e74d63b1d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b12-abc5-5951f10e80cb" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_019e02eb-cfc2-7aaf-9a08-743e74d63b1d" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LifeSettlementContractsFairValueMethodCarryingAmount_019e02eb-6e04-71cc-8933-e3cb270b9848" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LifeSettlementContractsFairValueMethodCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b12-abc5-5951f10e80cb" xlink:to="loc_us-gaap_LifeSettlementContractsFairValueMethodCarryingAmount_019e02eb-6e04-71cc-8933-e3cb270b9848" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_019e02ec-1607-7db2-b5de-566145bc90bc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b12-abc5-5951f10e80cb" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_019e02ec-1607-7db2-b5de-566145bc90bc" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019d2bfc-4668-7ad6-a74f-60a282fc7a37" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b12-abc5-5951f10e80cb" xlink:to="loc_us-gaap_Assets_019d2bfc-4668-7ad6-a74f-60a282fc7a37" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_DebtInstrumentCovenantAssetCoverageRatio_019d2bfc-4668-7407-b5e3-87bce9cadf18" xlink:href="abx-20260331.xsd#abx_DebtInstrumentCovenantAssetCoverageRatio"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b12-abc5-5951f10e80cb" xlink:to="loc_abx_DebtInstrumentCovenantAssetCoverageRatio_019d2bfc-4668-7407-b5e3-87bce9cadf18" xlink:type="arc" order="14"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/LONGTERMDEBTSponsorPIKNoteDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#LONGTERMDEBTSponsorPIKNoteDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/LONGTERMDEBTSponsorPIKNoteDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b43-b383-d09e5f72ab6e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019d2bfc-4668-70b6-b1c8-65f9e20fecf0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b43-b383-d09e5f72ab6e" xlink:to="loc_us-gaap_DebtInstrumentTable_019d2bfc-4668-70b6-b1c8-65f9e20fecf0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019d2bfc-4668-7583-b4d3-7fc135a14d60" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019d2bfc-4668-70b6-b1c8-65f9e20fecf0" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019d2bfc-4668-7583-b4d3-7fc135a14d60" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019d2bfc-4668-7583-b4d3-7fc135a14d60_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019d2bfc-4668-7583-b4d3-7fc135a14d60" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019d2bfc-4668-7583-b4d3-7fc135a14d60_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019d2bfc-4668-7d42-9f45-47a0ec9f8942" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019d2bfc-4668-7583-b4d3-7fc135a14d60" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019d2bfc-4668-7d42-9f45-47a0ec9f8942" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnsecuredDebtMember_019d2bfc-4668-7c3d-ab7f-e3a8b4633ace" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnsecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019d2bfc-4668-7d42-9f45-47a0ec9f8942" xlink:to="loc_us-gaap_UnsecuredDebtMember_019d2bfc-4668-7c3d-ab7f-e3a8b4633ace" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019d2bfc-4668-78c1-a908-b9098defe014" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019d2bfc-4668-70b6-b1c8-65f9e20fecf0" xlink:to="loc_us-gaap_DebtInstrumentAxis_019d2bfc-4668-78c1-a908-b9098defe014" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-4668-78c1-a908-b9098defe014_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019d2bfc-4668-78c1-a908-b9098defe014" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-4668-78c1-a908-b9098defe014_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-4668-79a5-94dc-4530dd475779" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019d2bfc-4668-78c1-a908-b9098defe014" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-4668-79a5-94dc-4530dd475779" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_SponsorPIKNoteMember_019d2bfc-4668-7e29-b5e3-9336b3b8e8fc" xlink:href="abx-20260331.xsd#abx_SponsorPIKNoteMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019d2bfc-4668-79a5-94dc-4530dd475779" xlink:to="loc_abx_SponsorPIKNoteMember_019d2bfc-4668-7e29-b5e3-9336b3b8e8fc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_019d2bfc-4668-787c-a69c-4c80265d34e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b43-b383-d09e5f72ab6e" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_019d2bfc-4668-787c-a69c-4c80265d34e7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019d2bfc-4668-7b37-ac33-a7975ce9bba3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b43-b383-d09e5f72ab6e" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019d2bfc-4668-7b37-ac33-a7975ce9bba3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_PaidInKindInterestAccrued_019d2bfc-4668-7d39-9b4d-159365ddb4ef" xlink:href="abx-20260331.xsd#abx_PaidInKindInterestAccrued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b43-b383-d09e5f72ab6e" xlink:to="loc_abx_PaidInKindInterestAccrued_019d2bfc-4668-7d39-9b4d-159365ddb4ef" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaidInKindInterest_019d2bfc-4668-7c78-9e3b-27d032b317ef" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaidInKindInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019d2bfc-4668-7b43-b383-d09e5f72ab6e" xlink:to="loc_us-gaap_PaidInKindInterest_019d2bfc-4668-7c78-9e3b-27d032b317ef" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/STOCKBASEDCOMPENSATIONNarrativeDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#STOCKBASEDCOMPENSATIONNarrativeDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/STOCKBASEDCOMPENSATIONNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019df963-36ac-77ee-8d28-b29a2c6c87fa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019d2bfc-4668-7590-ac88-8524c88144a2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019df963-36ac-77ee-8d28-b29a2c6c87fa" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019d2bfc-4668-7590-ac88-8524c88144a2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019df963-36ac-7818-af8f-328c7ed78a22" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019d2bfc-4668-7590-ac88-8524c88144a2" xlink:to="loc_us-gaap_AwardTypeAxis_019df963-36ac-7818-af8f-328c7ed78a22" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019df963-36ac-7818-af8f-328c7ed78a22_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019df963-36ac-7818-af8f-328c7ed78a22" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019df963-36ac-7818-af8f-328c7ed78a22_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019df963-36ac-70e1-89b6-85d1c660a2ce" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019df963-36ac-7818-af8f-328c7ed78a22" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019df963-36ac-70e1-89b6-85d1c660a2ce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019df963-36ac-7050-8c69-a60b3f77f925" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019df963-36ac-70e1-89b6-85d1c660a2ce" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019df963-36ac-7050-8c69-a60b3f77f925" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_RestrictedStockUnitsRSUsAndEmployeeStockOptionMember_019df963-8225-7186-a1a7-3be848677e49" xlink:href="abx-20260331.xsd#abx_RestrictedStockUnitsRSUsAndEmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019df963-36ac-70e1-89b6-85d1c660a2ce" xlink:to="loc_abx_RestrictedStockUnitsRSUsAndEmployeeStockOptionMember_019df963-8225-7186-a1a7-3be848677e49" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_019df963-36ac-7342-88e6-1cc73253b35b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019d2bfc-4668-7590-ac88-8524c88144a2" xlink:to="loc_us-gaap_PlanNameAxis_019df963-36ac-7342-88e6-1cc73253b35b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019df963-36ac-7342-88e6-1cc73253b35b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_019df963-36ac-7342-88e6-1cc73253b35b" xlink:to="loc_us-gaap_PlanNameDomain_019df963-36ac-7342-88e6-1cc73253b35b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019df963-36ac-739f-b6db-910d96659402" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_019df963-36ac-7342-88e6-1cc73253b35b" xlink:to="loc_us-gaap_PlanNameDomain_019df963-36ac-739f-b6db-910d96659402" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LongTermIncentivePlanMember_019df963-36ac-7517-91bd-b05eb2fffd12" xlink:href="abx-20260331.xsd#abx_LongTermIncentivePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019df963-36ac-739f-b6db-910d96659402" xlink:to="loc_abx_LongTermIncentivePlanMember_019df963-36ac-7517-91bd-b05eb2fffd12" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_019df963-8225-71ca-bc5c-2687ecb6009c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019d2bfc-4668-7590-ac88-8524c88144a2" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_019df963-8225-71ca-bc5c-2687ecb6009c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_019df963-8225-71ca-bc5c-2687ecb6009c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_019df963-8225-71ca-bc5c-2687ecb6009c" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_019df963-8225-71ca-bc5c-2687ecb6009c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_019df963-8225-711b-b73a-48321bb6f375" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_019df963-8225-71ca-bc5c-2687ecb6009c" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_019df963-8225-711b-b73a-48321bb6f375" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember_019df963-8225-7adc-8d0e-12a98c579bf4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfSalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_019df963-8225-711b-b73a-48321bb6f375" xlink:to="loc_us-gaap_CostOfSalesMember_019df963-8225-7adc-8d0e-12a98c579bf4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpenseMember_019df963-8225-72c8-b89a-3641a592ccd0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralAndAdministrativeExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_019df963-8225-711b-b73a-48321bb6f375" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpenseMember_019df963-8225-72c8-b89a-3641a592ccd0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_019df963-36ac-7e69-98a5-ef6fa4fdf667" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019df963-36ac-77ee-8d28-b29a2c6c87fa" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_019df963-36ac-7e69-98a5-ef6fa4fdf667" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesEntitledToForEachAward_019df963-36ac-7bfc-a092-a6c5f51703e7" xlink:href="abx-20260331.xsd#abx_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesEntitledToForEachAward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019df963-36ac-77ee-8d28-b29a2c6c87fa" xlink:to="loc_abx_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesEntitledToForEachAward_019df963-36ac-7bfc-a092-a6c5f51703e7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_019df963-64b2-7ed0-b9a7-b56959bbd51a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019df963-36ac-77ee-8d28-b29a2c6c87fa" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_019df963-64b2-7ed0-b9a7-b56959bbd51a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019df963-8225-7076-9b3a-c61e022ceebd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019df963-36ac-77ee-8d28-b29a2c6c87fa" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019df963-8225-7076-9b3a-c61e022ceebd" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_019df963-8225-7d98-9034-b9313fe09f49" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019df963-36ac-77ee-8d28-b29a2c6c87fa" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_019df963-8225-7d98-9034-b9313fe09f49" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_019df963-8225-762d-923e-71fa8d0ece51" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019df963-36ac-77ee-8d28-b29a2c6c87fa" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_019df963-8225-762d-923e-71fa8d0ece51" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/STOCKBASEDCOMPENSATIONRestrictedStockActivityDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#STOCKBASEDCOMPENSATIONRestrictedStockActivityDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/STOCKBASEDCOMPENSATIONRestrictedStockActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019d2bfc-4668-7ff2-845a-4b632ae1cd63" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019d2bfc-4668-7ff3-b72f-d62f438ed1a9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019d2bfc-4668-7ff2-845a-4b632ae1cd63" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019d2bfc-4668-7ff3-b72f-d62f438ed1a9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019d2bfc-4668-74a4-9092-9a7ce4e8a861" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019d2bfc-4668-7ff3-b72f-d62f438ed1a9" xlink:to="loc_us-gaap_AwardTypeAxis_019d2bfc-4668-74a4-9092-9a7ce4e8a861" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019d2bfc-4668-74a4-9092-9a7ce4e8a861_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019d2bfc-4668-74a4-9092-9a7ce4e8a861" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019d2bfc-4668-74a4-9092-9a7ce4e8a861_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019d2bfc-4668-7b30-b9fb-020237c27e05" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019d2bfc-4668-74a4-9092-9a7ce4e8a861" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019d2bfc-4668-7b30-b9fb-020237c27e05" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019d2bfc-4668-7bc7-b65a-1c466d7c6b92" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019d2bfc-4668-7b30-b9fb-020237c27e05" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019d2bfc-4668-7bc7-b65a-1c466d7c6b92" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019d2bfc-4668-71ce-9f56-3108010eadef" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019d2bfc-4668-7ff2-845a-4b632ae1cd63" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019d2bfc-4668-71ce-9f56-3108010eadef" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019d2bfc-4668-7122-ac6d-bceabf41ff98" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019d2bfc-4668-71ce-9f56-3108010eadef" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019d2bfc-4668-7122-ac6d-bceabf41ff98" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019d2bfc-4668-77f0-8b3a-a6bb9ba31082" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019d2bfc-4668-71ce-9f56-3108010eadef" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019d2bfc-4668-77f0-8b3a-a6bb9ba31082" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019d2bfc-4668-7074-a195-aad40fc2fbb3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019d2bfc-4668-71ce-9f56-3108010eadef" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019d2bfc-4668-7074-a195-aad40fc2fbb3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019d2bfc-4668-7fe4-9d52-24d95ac369f9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019d2bfc-4668-71ce-9f56-3108010eadef" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019d2bfc-4668-7fe4-9d52-24d95ac369f9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019d2bfc-4668-7826-9e40-955b90beb3dc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019d2bfc-4668-742f-a8d0-16f618ecd277" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019d2bfc-4668-7ff2-845a-4b632ae1cd63" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019d2bfc-4668-742f-a8d0-16f618ecd277" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019d2bfc-4668-768a-a228-509942021e42" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019d2bfc-4668-742f-a8d0-16f618ecd277" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019d2bfc-4668-768a-a228-509942021e42" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019d2bfc-4668-784a-bb82-48e2e1c4b571" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019d2bfc-4668-742f-a8d0-16f618ecd277" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019d2bfc-4668-784a-bb82-48e2e1c4b571" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019d2bfc-4668-76a6-ac1c-14c4e37a6545" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019d2bfc-4668-742f-a8d0-16f618ecd277" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019d2bfc-4668-76a6-ac1c-14c4e37a6545" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019d2bfc-4668-7c20-92c7-8bb70cdc8e50" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019d2bfc-4668-742f-a8d0-16f618ecd277" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019d2bfc-4668-7c20-92c7-8bb70cdc8e50" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019d2bfc-4668-77cb-b1f7-ff0364307987" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/RELATEDPARTYTRANSACTIONSNarrativeDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#RELATEDPARTYTRANSACTIONSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/RELATEDPARTYTRANSACTIONSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_019dd4f4-d4cf-7902-b982-7f487cb47448" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019d2bfc-4668-73e3-b9cf-333726869c73" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dd4f4-d4cf-7902-b982-7f487cb47448" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019d2bfc-4668-73e3-b9cf-333726869c73" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019dd4f4-d4cf-7878-bffe-5a3a08bd8784" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019d2bfc-4668-73e3-b9cf-333726869c73" xlink:to="loc_us-gaap_DebtInstrumentAxis_019dd4f4-d4cf-7878-bffe-5a3a08bd8784" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019dd4f4-d4cf-7878-bffe-5a3a08bd8784_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019dd4f4-d4cf-7878-bffe-5a3a08bd8784" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019dd4f4-d4cf-7878-bffe-5a3a08bd8784_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019dd4f4-d4cf-74fc-b8fb-6b092bb490fe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019dd4f4-d4cf-7878-bffe-5a3a08bd8784" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019dd4f4-d4cf-74fc-b8fb-6b092bb490fe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_SponsorPIKNoteMember_019dd4f4-d4cf-770b-971b-68d0a293d22d" xlink:href="abx-20260331.xsd#abx_SponsorPIKNoteMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019dd4f4-d4cf-74fc-b8fb-6b092bb490fe" xlink:to="loc_abx_SponsorPIKNoteMember_019dd4f4-d4cf-770b-971b-68d0a293d22d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019dd4f4-d4cf-7aa6-a5e1-1babb8d9dbdc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019d2bfc-4668-73e3-b9cf-333726869c73" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019dd4f4-d4cf-7aa6-a5e1-1babb8d9dbdc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019dd4f4-d4cf-7aa6-a5e1-1babb8d9dbdc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019dd4f4-d4cf-7aa6-a5e1-1babb8d9dbdc" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019dd4f4-d4cf-7aa6-a5e1-1babb8d9dbdc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019dd4f4-d4cf-76f0-986f-4453c23def8d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019dd4f4-d4cf-7aa6-a5e1-1babb8d9dbdc" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019dd4f4-d4cf-76f0-986f-4453c23def8d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnsecuredDebtMember_019dd4f4-d4cf-7eac-940b-3ef7484e7978" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnsecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019dd4f4-d4cf-76f0-986f-4453c23def8d" xlink:to="loc_us-gaap_UnsecuredDebtMember_019dd4f4-d4cf-7eac-940b-3ef7484e7978" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019dd4f4-d4cf-7bbd-b38a-f434c9cae7b1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019d2bfc-4668-73e3-b9cf-333726869c73" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019dd4f4-d4cf-7bbd-b38a-f434c9cae7b1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019dd4f4-d4cf-7bbd-b38a-f434c9cae7b1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019dd4f4-d4cf-7bbd-b38a-f434c9cae7b1" xlink:to="loc_us-gaap_RelatedPartyDomain_019dd4f4-d4cf-7bbd-b38a-f434c9cae7b1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019dd4f4-d4cf-7085-9b09-227b4a8afc6c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019dd4f4-d4cf-7bbd-b38a-f434c9cae7b1" xlink:to="loc_us-gaap_RelatedPartyDomain_019dd4f4-d4cf-7085-9b09-227b4a8afc6c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019dd4f4-d4cf-7cf0-944a-22baeb574d99" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019dd4f4-d4cf-7085-9b09-227b4a8afc6c" xlink:to="loc_us-gaap_RelatedPartyMember_019dd4f4-d4cf-7cf0-944a-22baeb574d99" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_019dd4f4-d4cf-7a1b-b959-9a8fc6810cd2" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019d2bfc-4668-73e3-b9cf-333726869c73" xlink:to="loc_srt_CounterpartyNameAxis_019dd4f4-d4cf-7a1b-b959-9a8fc6810cd2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019dd4f4-d4cf-7a1b-b959-9a8fc6810cd2_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_019dd4f4-d4cf-7a1b-b959-9a8fc6810cd2" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019dd4f4-d4cf-7a1b-b959-9a8fc6810cd2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019dd4f4-d4cf-7c88-893f-9cb8e24c775f" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_019dd4f4-d4cf-7a1b-b959-9a8fc6810cd2" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019dd4f4-d4cf-7c88-893f-9cb8e24c775f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_CarlisleFundsMember_019dd4f4-d4cf-7b44-bbf3-d55ce0ba2b86" xlink:href="abx-20260331.xsd#abx_CarlisleFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019dd4f4-d4cf-7c88-893f-9cb8e24c775f" xlink:to="loc_abx_CarlisleFundsMember_019dd4f4-d4cf-7b44-bbf3-d55ce0ba2b86" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LPFundsMember_019dd4f4-d4cf-74ec-beea-6c1823d5885d" xlink:href="abx-20260331.xsd#abx_LPFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019dd4f4-d4cf-7c88-893f-9cb8e24c775f" xlink:to="loc_abx_LPFundsMember_019dd4f4-d4cf-74ec-beea-6c1823d5885d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_SecuritizedEntityMember_019dd4f4-d4cf-74b7-bdd6-2c5af76daab7" xlink:href="abx-20260331.xsd#abx_SecuritizedEntityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019dd4f4-d4cf-7c88-893f-9cb8e24c775f" xlink:to="loc_abx_SecuritizedEntityMember_019dd4f4-d4cf-74b7-bdd6-2c5af76daab7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_CarlisleFundsAndLPFundsMember_019dd4f4-d4cf-76a6-b6ff-ca64c38ca6eb" xlink:href="abx-20260331.xsd#abx_CarlisleFundsAndLPFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019dd4f4-d4cf-7c88-893f-9cb8e24c775f" xlink:to="loc_abx_CarlisleFundsAndLPFundsMember_019dd4f4-d4cf-76a6-b6ff-ca64c38ca6eb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionAxis_019dd4f4-d4cf-750b-8eb7-9f79efe335fa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019d2bfc-4668-73e3-b9cf-333726869c73" xlink:to="loc_us-gaap_RelatedPartyTransactionAxis_019dd4f4-d4cf-750b-8eb7-9f79efe335fa" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_019dd4f4-d4cf-750b-8eb7-9f79efe335fa_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_019dd4f4-d4cf-750b-8eb7-9f79efe335fa" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_019dd4f4-d4cf-750b-8eb7-9f79efe335fa_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_019dd4f4-d4cf-7b16-992f-0d177b7bab1c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_019dd4f4-d4cf-750b-8eb7-9f79efe335fa" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_019dd4f4-d4cf-7b16-992f-0d177b7bab1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_ServiceFeeAgreementMember_019dd4f4-d4cf-7823-8672-16bf0bba8f95" xlink:href="abx-20260331.xsd#abx_ServiceFeeAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_019dd4f4-d4cf-7b16-992f-0d177b7bab1c" xlink:to="loc_abx_ServiceFeeAgreementMember_019dd4f4-d4cf-7823-8672-16bf0bba8f95" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_PurchaseOfPoliciesMember_019dd4f4-d4cf-7dc1-a04b-6dac51d3169a" xlink:href="abx-20260331.xsd#abx_PurchaseOfPoliciesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_019dd4f4-d4cf-7b16-992f-0d177b7bab1c" xlink:to="loc_abx_PurchaseOfPoliciesMember_019dd4f4-d4cf-7dc1-a04b-6dac51d3169a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019dd4f4-d4cf-7cb3-b161-930727c0f0d6" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019d2bfc-4668-73e3-b9cf-333726869c73" xlink:to="loc_srt_RangeAxis_019dd4f4-d4cf-7cb3-b161-930727c0f0d6" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019dd4f4-d4cf-7cb3-b161-930727c0f0d6_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019dd4f4-d4cf-7cb3-b161-930727c0f0d6" xlink:to="loc_srt_RangeMember_019dd4f4-d4cf-7cb3-b161-930727c0f0d6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019dd4f4-d4cf-730d-8a7f-b233f1557105" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019dd4f4-d4cf-7cb3-b161-930727c0f0d6" xlink:to="loc_srt_RangeMember_019dd4f4-d4cf-730d-8a7f-b233f1557105" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019dd4f4-d4cf-7d19-aca5-8328902d1fe9" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019dd4f4-d4cf-730d-8a7f-b233f1557105" xlink:to="loc_srt_MinimumMember_019dd4f4-d4cf-7d19-aca5-8328902d1fe9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019dd4f4-d4cf-757b-b0b6-6e49ece2f9d0" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019dd4f4-d4cf-730d-8a7f-b233f1557105" xlink:to="loc_srt_MaximumMember_019dd4f4-d4cf-757b-b0b6-6e49ece2f9d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019dd4f4-d4cf-7ee7-834d-b739e5d985b8" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019d2bfc-4668-73e3-b9cf-333726869c73" xlink:to="loc_srt_ProductOrServiceAxis_019dd4f4-d4cf-7ee7-834d-b739e5d985b8" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019dd4f4-d4cf-7ee7-834d-b739e5d985b8_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019dd4f4-d4cf-7ee7-834d-b739e5d985b8" xlink:to="loc_srt_ProductsAndServicesDomain_019dd4f4-d4cf-7ee7-834d-b739e5d985b8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019dd4f4-d4cf-7f82-928f-c566acaeda5e" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019dd4f4-d4cf-7ee7-834d-b739e5d985b8" xlink:to="loc_srt_ProductsAndServicesDomain_019dd4f4-d4cf-7f82-928f-c566acaeda5e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetManagement1Member_019dd4f4-d4cf-784d-bce9-b06bcbfaae97" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetManagement1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019dd4f4-d4cf-7f82-928f-c566acaeda5e" xlink:to="loc_us-gaap_AssetManagement1Member_019dd4f4-d4cf-784d-bce9-b06bcbfaae97" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSolutionsMember_019dd4f4-d4cf-7fb7-8bc3-e0f50d4c7a49" xlink:href="abx-20260331.xsd#abx_LifeSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019dd4f4-d4cf-7f82-928f-c566acaeda5e" xlink:to="loc_abx_LifeSolutionsMember_019dd4f4-d4cf-7fb7-8bc3-e0f50d4c7a49" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_019dd4f4-d4cf-7f85-864c-eedccecc9de0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dd4f4-d4cf-7902-b982-7f487cb47448" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_019dd4f4-d4cf-7f85-864c-eedccecc9de0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSettlementContractsServicingFeePerContractPerYear_019dd4f4-d4cf-7ccf-a5a5-eb5afadc467a" xlink:href="abx-20260331.xsd#abx_LifeSettlementContractsServicingFeePerContractPerYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dd4f4-d4cf-7902-b982-7f487cb47448" xlink:to="loc_abx_LifeSettlementContractsServicingFeePerContractPerYear_019dd4f4-d4cf-7ccf-a5a5-eb5afadc467a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionRate_019dd4f4-d4cf-7069-acfd-0f71431335a9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dd4f4-d4cf-7902-b982-7f487cb47448" xlink:to="loc_us-gaap_RelatedPartyTransactionRate_019dd4f4-d4cf-7069-acfd-0f71431335a9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_019dd4f4-d4cf-75aa-bed2-9db8484626af" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dd4f4-d4cf-7902-b982-7f487cb47448" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_019dd4f4-d4cf-75aa-bed2-9db8484626af" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetNoncurrent_019dd4f4-d4cf-7383-9f26-3901aee8ef6d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableNetNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dd4f4-d4cf-7902-b982-7f487cb47448" xlink:to="loc_us-gaap_AccountsReceivableNetNoncurrent_019dd4f4-d4cf-7383-9f26-3901aee8ef6d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionPurchasesFromRelatedParty_019dd4f4-d4cf-70d3-9748-a311fb3febf1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionPurchasesFromRelatedParty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dd4f4-d4cf-7902-b982-7f487cb47448" xlink:to="loc_us-gaap_RelatedPartyTransactionPurchasesFromRelatedParty_019dd4f4-d4cf-70d3-9748-a311fb3febf1" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019dd4f4-f43f-7f1b-8496-5f7d0d358abb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dd4f4-d4cf-7902-b982-7f487cb47448" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019dd4f4-f43f-7f1b-8496-5f7d0d358abb" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019dd4f5-12c6-7cb5-90df-1543fd2dd3ec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dd4f4-d4cf-7902-b982-7f487cb47448" xlink:to="loc_us-gaap_Revenues_019dd4f5-12c6-7cb5-90df-1543fd2dd3ec" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LifeSettlementContractsFairValueMethodGainLoss_019dd4f5-12c6-7338-bc72-3ee00cf55d02" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LifeSettlementContractsFairValueMethodGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dd4f4-d4cf-7902-b982-7f487cb47448" xlink:to="loc_us-gaap_LifeSettlementContractsFairValueMethodGainLoss_019dd4f5-12c6-7338-bc72-3ee00cf55d02" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LifeSettlementContractsFairValueMethodUnrealizedGainLoss_019dd4f5-12c6-7b5d-bca1-c955ae6babbb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LifeSettlementContractsFairValueMethodUnrealizedGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dd4f4-d4cf-7902-b982-7f487cb47448" xlink:to="loc_us-gaap_LifeSettlementContractsFairValueMethodUnrealizedGainLoss_019dd4f5-12c6-7b5d-bca1-c955ae6babbb" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSettlementContractsFairValueMethodPremiumsPaidOnSoldPolicies_019dd4f5-12c6-7217-9bb5-26bd2febd386" xlink:href="abx-20260331.xsd#abx_LifeSettlementContractsFairValueMethodPremiumsPaidOnSoldPolicies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dd4f4-d4cf-7902-b982-7f487cb47448" xlink:to="loc_abx_LifeSettlementContractsFairValueMethodPremiumsPaidOnSoldPolicies_019dd4f5-12c6-7217-9bb5-26bd2febd386" xlink:type="arc" order="10"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/RELATEDPARTYTRANSACTIONSRevenueRecognizedDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#RELATEDPARTYTRANSACTIONSRevenueRecognizedDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/RELATEDPARTYTRANSACTIONSRevenueRecognizedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_019d2bfc-4668-79e0-a5c9-61526ce366a3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019d2bfc-4668-7860-8530-17b47cc72cac" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019d2bfc-4668-79e0-a5c9-61526ce366a3" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019d2bfc-4668-7860-8530-17b47cc72cac" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-4668-7c9b-8b36-a66ee415acb2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019d2bfc-4668-7860-8530-17b47cc72cac" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-4668-7c9b-8b36-a66ee415acb2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019d2bfc-4668-7c9b-8b36-a66ee415acb2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-4668-7c9b-8b36-a66ee415acb2" xlink:to="loc_us-gaap_RelatedPartyDomain_019d2bfc-4668-7c9b-8b36-a66ee415acb2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019d2bfc-4668-73ab-9478-220424d99006" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2bfc-4668-7c9b-8b36-a66ee415acb2" xlink:to="loc_us-gaap_RelatedPartyDomain_019d2bfc-4668-73ab-9478-220424d99006" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019d2bfc-4668-7cf1-907c-38e7bdb37a0a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019d2bfc-4668-73ab-9478-220424d99006" xlink:to="loc_us-gaap_RelatedPartyMember_019d2bfc-4668-7cf1-907c-38e7bdb37a0a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019d2bfc-4668-7b2a-bbaf-7d6b607a87ba" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019d2bfc-4668-7860-8530-17b47cc72cac" xlink:to="loc_srt_ProductOrServiceAxis_019d2bfc-4668-7b2a-bbaf-7d6b607a87ba" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019d2bfc-4668-7b2a-bbaf-7d6b607a87ba_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019d2bfc-4668-7b2a-bbaf-7d6b607a87ba" xlink:to="loc_srt_ProductsAndServicesDomain_019d2bfc-4668-7b2a-bbaf-7d6b607a87ba_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019d2bfc-4668-78ec-951a-5d1de87147e2" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019d2bfc-4668-7b2a-bbaf-7d6b607a87ba" xlink:to="loc_srt_ProductsAndServicesDomain_019d2bfc-4668-78ec-951a-5d1de87147e2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetManagement1Member_019d2bfc-4668-7fdb-a917-7b40aa37332a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetManagement1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019d2bfc-4668-78ec-951a-5d1de87147e2" xlink:to="loc_us-gaap_AssetManagement1Member_019d2bfc-4668-7fdb-a917-7b40aa37332a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LifeSolutionsMember_019d2bfc-4668-796e-a3bb-e17fa223cead" xlink:href="abx-20260331.xsd#abx_LifeSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019d2bfc-4668-78ec-951a-5d1de87147e2" xlink:to="loc_abx_LifeSolutionsMember_019d2bfc-4668-796e-a3bb-e17fa223cead" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_019d2bfc-4668-711e-af92-ec980971c865" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019d2bfc-4668-7860-8530-17b47cc72cac" xlink:to="loc_srt_CounterpartyNameAxis_019d2bfc-4668-711e-af92-ec980971c865" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019d2bfc-4668-711e-af92-ec980971c865_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_019d2bfc-4668-711e-af92-ec980971c865" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019d2bfc-4668-711e-af92-ec980971c865_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019d2bfc-4668-7369-ade2-e7874bfcdec0" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_019d2bfc-4668-711e-af92-ec980971c865" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019d2bfc-4668-7369-ade2-e7874bfcdec0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_CarlisleFundsMember_019d2bfc-4668-7374-9060-8e31d4123b12" xlink:href="abx-20260331.xsd#abx_CarlisleFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019d2bfc-4668-7369-ade2-e7874bfcdec0" xlink:to="loc_abx_CarlisleFundsMember_019d2bfc-4668-7374-9060-8e31d4123b12" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_abx_LPFundsMember_019d2bfc-4668-7848-beaf-4e58552352b9" xlink:href="abx-20260331.xsd#abx_LPFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019d2bfc-4668-7369-ade2-e7874bfcdec0" xlink:to="loc_abx_LPFundsMember_019d2bfc-4668-7848-beaf-4e58552352b9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019d2bfc-4668-749b-8b98-939fffd5c725" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019d2bfc-4668-79e0-a5c9-61526ce366a3" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019d2bfc-4668-749b-8b98-939fffd5c725" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019d2bfc-4668-7e0a-95a2-aee7f142da60" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019d2bfc-4668-79e0-a5c9-61526ce366a3" xlink:to="loc_us-gaap_Revenues_019d2bfc-4668-7e0a-95a2-aee7f142da60" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/EARNINGSPERSHAREEarningsPerShareBasicandDilutedDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#EARNINGSPERSHAREEarningsPerShareBasicandDilutedDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/EARNINGSPERSHAREEarningsPerShareBasicandDilutedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019d2bfc-4668-76f1-a709-d98cc5d013ae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019d2bfc-4668-736d-aece-f8eb24260d6a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019d2bfc-4668-76f1-a709-d98cc5d013ae" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019d2bfc-4668-736d-aece-f8eb24260d6a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019d2bfc-4668-7884-a6a0-7d1e957dd44a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019d2bfc-4668-736d-aece-f8eb24260d6a" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019d2bfc-4668-7884-a6a0-7d1e957dd44a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019d2bfc-4668-7884-a6a0-7d1e957dd44a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019d2bfc-4668-7884-a6a0-7d1e957dd44a" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019d2bfc-4668-7884-a6a0-7d1e957dd44a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019d2bfc-4668-707d-8a0f-f4236183f02d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019d2bfc-4668-7884-a6a0-7d1e957dd44a" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019d2bfc-4668-707d-8a0f-f4236183f02d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019d2bfc-4668-7840-a37a-8286a5a3a758" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019d2bfc-4668-707d-8a0f-f4236183f02d" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019d2bfc-4668-7840-a37a-8286a5a3a758" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019d2bfc-4668-7a45-8841-601a8d854089" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019d2bfc-4668-76f1-a709-d98cc5d013ae" xlink:to="loc_us-gaap_ProfitLoss_019d2bfc-4668-7a45-8841-601a8d854089" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019d2bfc-4668-7c3f-afe7-a706ed5206ac" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019d2bfc-4668-76f1-a709-d98cc5d013ae" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019d2bfc-4668-7c3f-afe7-a706ed5206ac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockDividendsIncomeStatementImpact_019d2bfc-4668-7f35-96cc-3e0904e3b7ef" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockDividendsIncomeStatementImpact"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019d2bfc-4668-76f1-a709-d98cc5d013ae" xlink:to="loc_us-gaap_PreferredStockDividendsIncomeStatementImpact_019d2bfc-4668-7f35-96cc-3e0904e3b7ef" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_019d2bfc-4668-7e16-9946-a10a1e60a57f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019d2bfc-4668-76f1-a709-d98cc5d013ae" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_019d2bfc-4668-7e16-9946-a10a1e60a57f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019d2bfc-4668-7c21-aa82-9e30f6441388" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019d2bfc-4668-76f1-a709-d98cc5d013ae" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019d2bfc-4668-7c21-aa82-9e30f6441388" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_019d2bfc-4668-7219-8df4-765926da8691" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019d2bfc-4668-76f1-a709-d98cc5d013ae" xlink:to="loc_us-gaap_EarningsPerShareBasic_019d2bfc-4668-7219-8df4-765926da8691" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_019d2bfc-4668-73ba-94d6-ccff5b270e1d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019d2bfc-4668-76f1-a709-d98cc5d013ae" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_019d2bfc-4668-73ba-94d6-ccff5b270e1d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019dd63c-4ca1-7162-a389-f690970234fa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_019d2bfc-4668-7db8-a6ab-b652a08f3d1f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019d2bfc-4668-76f1-a709-d98cc5d013ae" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_019d2bfc-4668-7db8-a6ab-b652a08f3d1f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToConversionOfPreferredStock_019d2bfc-4668-7f3e-84fe-4629de1c44e2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncrementalCommonSharesAttributableToConversionOfPreferredStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019d2bfc-4668-76f1-a709-d98cc5d013ae" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToConversionOfPreferredStock_019d2bfc-4668-7f3e-84fe-4629de1c44e2" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019d2bfc-4668-78e0-96a6-26ba00e98a35" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019d2bfc-4668-76f1-a709-d98cc5d013ae" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019d2bfc-4668-78e0-96a6-26ba00e98a35" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_019d2bfc-4668-722d-86a6-675e818cc732" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019d2bfc-4668-76f1-a709-d98cc5d013ae" xlink:to="loc_us-gaap_EarningsPerShareDiluted_019d2bfc-4668-722d-86a6-675e818cc732" xlink:type="arc" order="11"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://abacusgm.com/role/EARNINGSPERSHAREPotentiallyDilutiveOutstandingSecuritiesDetails" xlink:type="simple" xlink:href="abx-20260331.xsd#EARNINGSPERSHAREPotentiallyDilutiveOutstandingSecuritiesDetails"/>
  <link:definitionLink xlink:role="http://abacusgm.com/role/EARNINGSPERSHAREPotentiallyDilutiveOutstandingSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019d2bfc-4668-74de-968e-3b4947c15c60" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019d2bfc-4668-7e94-9f66-eedf3affea9e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019d2bfc-4668-74de-968e-3b4947c15c60" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019d2bfc-4668-7e94-9f66-eedf3affea9e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019d2bfc-4668-739a-a6f6-e1af32ab423c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019d2bfc-4668-7e94-9f66-eedf3affea9e" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019d2bfc-4668-739a-a6f6-e1af32ab423c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019d2bfc-4668-739a-a6f6-e1af32ab423c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019d2bfc-4668-739a-a6f6-e1af32ab423c" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019d2bfc-4668-739a-a6f6-e1af32ab423c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019d2bfc-4668-7680-b8d0-6a806f28f311" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019d2bfc-4668-739a-a6f6-e1af32ab423c" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019d2bfc-4668-7680-b8d0-6a806f28f311" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019d2bfc-4668-74cd-99f0-863fcea2c926" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019d2bfc-4668-7680-b8d0-6a806f28f311" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019d2bfc-4668-74cd-99f0-863fcea2c926" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_019d2bfc-4668-7f33-aba5-81c7863e5d48" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019d2bfc-4668-7680-b8d0-6a806f28f311" xlink:to="loc_us-gaap_EmployeeStockOptionMember_019d2bfc-4668-7f33-aba5-81c7863e5d48" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019d2bfc-4668-7d24-8935-4c9e0f631531" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019d2bfc-4668-74de-968e-3b4947c15c60" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019d2bfc-4668-7d24-8935-4c9e0f631531" xlink:type="arc" order="0"/>
  </link:definitionLink>
</link:linkbase>
