<?xml version="1.0" encoding="us-ascii"?>
<!-- XBRL document created with Praxa -->
<!-- Copyright (c) 2026 Praxa LLC. All Rights Reserved.-->
<!-- Creation Date: 2026-08-14T15:58:20.7045+00:00 -->
<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:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/notAll" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#notAll" xlink:type="simple" />
  <link:roleRef roleURI="http://dmaacorp.com/20260630/role/RelatedPartiesDetails" xlink:href="dmiiu-20260630.xsd#RelatedPartiesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://dmaacorp.com/20260630/role/ShareholdersDeficitDetails" xlink:href="dmiiu-20260630.xsd#ShareholdersDeficitDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://dmaacorp.com/20260630/role/SegmentInformationDetails" xlink:href="dmiiu-20260630.xsd#SegmentInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://dmaacorp.com/20260630/role/StatementsofOperationsUnaudited" xlink:href="dmiiu-20260630.xsd#StatementsofOperationsUnaudited" xlink:type="simple" />
  <link:roleRef roleURI="http://dmaacorp.com/20260630/role/StatementsofOperationsUnauditedParentheticals" xlink:href="dmiiu-20260630.xsd#StatementsofOperationsUnauditedParentheticals" xlink:type="simple" />
  <link:roleRef roleURI="http://dmaacorp.com/20260630/role/DescriptionofOrganizationBusinessOperationsandGoingConcernDetails" xlink:href="dmiiu-20260630.xsd#DescriptionofOrganizationBusinessOperationsandGoingConcernDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://dmaacorp.com/20260630/role/SummaryofSignificantAccountingPoliciesDetails" xlink:href="dmiiu-20260630.xsd#SummaryofSignificantAccountingPoliciesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://dmaacorp.com/20260630/role/SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetails" xlink:href="dmiiu-20260630.xsd#SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://dmaacorp.com/20260630/role/InitialPublicOfferingDetails" xlink:href="dmiiu-20260630.xsd#InitialPublicOfferingDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://dmaacorp.com/20260630/role/Cover" xlink:href="dmiiu-20260630.xsd#Cover" xlink:type="simple" />
  <link:roleRef roleURI="http://dmaacorp.com/20260630/role/PromissoryNotesDetails" xlink:href="dmiiu-20260630.xsd#PromissoryNotesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://dmaacorp.com/20260630/role/CommitmentsandContingenciesDetails" xlink:href="dmiiu-20260630.xsd#CommitmentsandContingenciesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://dmaacorp.com/20260630/role/FairValueMeasurementsScheduleofFairValueHierarchyoftheValuationInputsDetails" xlink:href="dmiiu-20260630.xsd#FairValueMeasurementsScheduleofFairValueHierarchyoftheValuationInputsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://dmaacorp.com/20260630/role/PrivatePlacementDetails" xlink:href="dmiiu-20260630.xsd#PrivatePlacementDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://dmaacorp.com/20260630/role/StatementsofChangesInShareholdersDeficitUnaudited" xlink:href="dmiiu-20260630.xsd#StatementsofChangesInShareholdersDeficitUnaudited" xlink:type="simple" />
  <link:definitionLink xlink:role="http://dmaacorp.com/20260630/role/RelatedPartiesDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_AdministrativeSupportAgreementMember" xlink:label="dmiiu_AdministrativeSupportAgreementMember_1317" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_CEOCompensationAgreementMember" xlink:label="dmiiu_CEOCompensationAgreementMember_8851" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_CFOAgreementMember" xlink:label="dmiiu_CFOAgreementMember_1318" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_ConsultingAgreementMember" xlink:label="dmiiu_ConsultingAgreementMember_7629" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_FounderShares1Member" xlink:label="dmiiu_FounderShares1Member_1323" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_SponsorMember" xlink:label="dmiiu_SponsorMember_1316" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember_7669" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialPaperMember" xlink:label="us-gaap_CommercialPaperMember_1327" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember_1313" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember_8847" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember" xlink:label="srt_MinimumMember_8848" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember" xlink:label="srt_RangeMember_8846" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyMember" xlink:label="us-gaap_RelatedPartyMember_1319" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OverAllotmentOptionMember" xlink:label="us-gaap_OverAllotmentOptionMember_1310" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IPOMember" xlink:label="us-gaap_IPOMember_7659" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_AdvisoryFees" xlink:label="dmiiu_AdvisoryFees_7646" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_ConvertibleUnitPrice" xlink:label="dmiiu_ConvertibleUnitPrice_1353" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_DebtInstrumentAmountConvertibleToEquityMaximum" xlink:label="dmiiu_DebtInstrumentAmountConvertibleToEquityMaximum_1352" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_DueToSponsor" xlink:label="dmiiu_DueToSponsor_1349" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_ExpirationTerm" xlink:label="dmiiu_ExpirationTerm_7615" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent_8918" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_NumberOfSharesExchanged" xlink:label="dmiiu_NumberOfSharesExchanged_8803" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_PercentageOfIssuedAndOutstandingSharesAfterInitialPublicOffering" xlink:label="dmiiu_PercentageOfIssuedAndOutstandingSharesAfterInitialPublicOffering_1336" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_PercentageOfSharesRemainingSixMonthOfInitialBusinessCombination" xlink:label="dmiiu_PercentageOfSharesRemainingSixMonthOfInitialBusinessCombination_1341" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_PercentageOfShareswhichEarlierOfSixMonthOfInitialBusinessCombination" xlink:label="dmiiu_PercentageOfShareswhichEarlierOfSixMonthOfInitialBusinessCombination_1337" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_RelatedPartiesDetailsTable" xlink:label="dmiiu_RelatedPartiesDetailsTable_1307" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_RelatedPartyTransactionCompensationAmountPayable" xlink:label="dmiiu_RelatedPartyTransactionCompensationAmountPayable_8852" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_RelatedPartyTransactionCompensationAmountPerMonth" xlink:label="dmiiu_RelatedPartyTransactionCompensationAmountPerMonth_8850" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_RelatedPartyTransactionCompensationDeferredAmount" xlink:label="dmiiu_RelatedPartyTransactionCompensationDeferredAmount_8853" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_RelatedPartyTransactionOfficeSpaceExpenses" xlink:label="dmiiu_RelatedPartyTransactionOfficeSpaceExpenses_1342" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_RelatedPartyTransactionSharesOfTransaction" xlink:label="dmiiu_RelatedPartyTransactionSharesOfTransaction_8841" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_RepaymentOfOfferingCosts" xlink:label="dmiiu_RepaymentOfOfferingCosts_7649" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_SponsorRepaid" xlink:label="dmiiu_SponsorRepaid_8840" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_TransferAssignOrSellAnySharesOrWarrantsAfterCompletionOfInitialBusinessCombinationThresholdConsecutiveTradingDays" xlink:label="dmiiu_TransferAssignOrSellAnySharesOrWarrantsAfterCompletionOfInitialBusinessCombinationThresholdConsecutiveTradingDays_1340" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_TransferAssignOrSellAnySharesOrWarrantsAfterCompletionOfInitialBusinessCombinationThresholdTradingDays" xlink:label="dmiiu_TransferAssignOrSellAnySharesOrWarrantsAfterCompletionOfInitialBusinessCombinationThresholdTradingDays_1339" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RepaymentsOfNotesPayable" xlink:label="us-gaap_RepaymentsOfNotesPayable_7648" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RepaymentsOfDebt" xlink:label="us-gaap_RepaymentsOfDebt_8804" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1321" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionsAbstract" xlink:label="us-gaap_RelatedPartyTransactionsAbstract_1306" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="us-gaap_RelatedPartyTransactionLineItems_1331" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionDomain" xlink:label="us-gaap_RelatedPartyTransactionDomain_1315" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionAxis" xlink:label="us-gaap_RelatedPartyTransactionAxis_1314" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1312" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_7602" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityAxis" xlink:label="us-gaap_CreditFacilityAxis_1325" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain" xlink:label="us-gaap_CreditFacilityDomain_1326" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="us-gaap_GeneralAndAdministrativeExpense_1345" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherExpenses" xlink:label="us-gaap_OtherExpenses_8911" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInDueFromRelatedParties" xlink:label="us-gaap_IncreaseDecreaseInDueFromRelatedParties_7651" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockPricePerShare" xlink:label="us-gaap_SaleOfStockPricePerShare_1338" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1309" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_WorkingCapital" xlink:label="dmiiu_WorkingCapital_7647" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_WorkingCapitalLoans" xlink:label="dmiiu_WorkingCapitalLoans_1354" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis_8845" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedLiabilitiesCurrentAndNoncurrent" xlink:label="us-gaap_AccruedLiabilitiesCurrentAndNoncurrent_1344" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdministrativeFeesExpense" xlink:label="us-gaap_AdministrativeFeesExpense_1343" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_8873" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_ServiceFeesPerMonth" xlink:label="dmiiu_ServiceFeesPerMonth_8908" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_ServiceFeesPerYear" xlink:label="dmiiu_ServiceFeesPerYear_8909" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermBorrowings" xlink:label="us-gaap_ShortTermBorrowings_1346" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis_1311" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues_1332" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationForfeited" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationForfeited_1335" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_1308" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="us-gaap_TypeOfArrangementAxis_7628" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain_1322" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember_7669_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember" xlink:label="srt_RangeMember_8846_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionDomain" xlink:label="us-gaap_RelatedPartyTransactionDomain_1315_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1312_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain" xlink:label="us-gaap_CreditFacilityDomain_1326_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1309_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain_1322_default" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionDomain_1315" xlink:to="dmiiu_AdministrativeSupportAgreementMember_1317" />
    <link:definitionArc xlink:type="arc" order="689.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionDomain_1315" xlink:to="dmiiu_CEOCompensationAgreementMember_8851" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionDomain_1315" xlink:to="dmiiu_CFOAgreementMember_1318" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ArrangementsAndNonarrangementTransactionsMember_7669" xlink:to="dmiiu_ConsultingAgreementMember_7629" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain_1322" xlink:to="dmiiu_FounderShares1Member_1323" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionDomain_1315" xlink:to="dmiiu_SponsorMember_1316" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_TypeOfArrangementAxis_7628" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember_7669" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CreditFacilityDomain_1326" xlink:to="us-gaap_CommercialPaperMember_1327" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1312" xlink:to="us-gaap_CommonStockMember_1313" />
    <link:definitionArc xlink:type="arc" order="686.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember_8846" xlink:to="srt_MaximumMember_8847" />
    <link:definitionArc xlink:type="arc" order="687.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember_8846" xlink:to="srt_MinimumMember_8848" />
    <link:definitionArc xlink:type="arc" order="685.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_RangeAxis_8845" xlink:to="srt_RangeMember_8846" />
    <link:definitionArc xlink:type="arc" order="14.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionDomain_1315" xlink:to="us-gaap_RelatedPartyMember_1319" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1309" xlink:to="us-gaap_OverAllotmentOptionMember_1310" />
    <link:definitionArc xlink:type="arc" order="536.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1309" xlink:to="us-gaap_IPOMember_7659" />
    <link:definitionArc xlink:type="arc" order="31.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_AdvisoryFees_7646" />
    <link:definitionArc xlink:type="arc" order="42.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_ConvertibleUnitPrice_1353" />
    <link:definitionArc xlink:type="arc" order="41.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_DebtInstrumentAmountConvertibleToEquityMaximum_1352" />
    <link:definitionArc xlink:type="arc" order="32.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_DueToSponsor_1349" />
    <link:definitionArc xlink:type="arc" order="18.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_ExpirationTerm_7615" />
    <link:definitionArc xlink:type="arc" order="751.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent_8918" />
    <link:definitionArc xlink:type="arc" order="14.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_NumberOfSharesExchanged_8803" />
    <link:definitionArc xlink:type="arc" order="17.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_PercentageOfIssuedAndOutstandingSharesAfterInitialPublicOffering_1336" />
    <link:definitionArc xlink:type="arc" order="23.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_PercentageOfSharesRemainingSixMonthOfInitialBusinessCombination_1341" />
    <link:definitionArc xlink:type="arc" order="19.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_PercentageOfShareswhichEarlierOfSixMonthOfInitialBusinessCombination_1337" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_RelatedPartiesDetailsTable_1307" />
    <link:definitionArc xlink:type="arc" order="690.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_RelatedPartyTransactionCompensationAmountPayable_8852" />
    <link:definitionArc xlink:type="arc" order="688.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_RelatedPartyTransactionCompensationAmountPerMonth_8850" />
    <link:definitionArc xlink:type="arc" order="691.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_RelatedPartyTransactionCompensationDeferredAmount_8853" />
    <link:definitionArc xlink:type="arc" order="24.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_RelatedPartyTransactionOfficeSpaceExpenses_1342" />
    <link:definitionArc xlink:type="arc" order="680.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_RelatedPartyTransactionSharesOfTransaction_8841" />
    <link:definitionArc xlink:type="arc" order="35.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_RepaymentOfOfferingCosts_7649" />
    <link:definitionArc xlink:type="arc" order="679.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_SponsorRepaid_8840" />
    <link:definitionArc xlink:type="arc" order="22.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_TransferAssignOrSellAnySharesOrWarrantsAfterCompletionOfInitialBusinessCombinationThresholdConsecutiveTradingDays_1340" />
    <link:definitionArc xlink:type="arc" order="21.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_TransferAssignOrSellAnySharesOrWarrantsAfterCompletionOfInitialBusinessCombinationThresholdTradingDays_1339" />
    <link:definitionArc xlink:type="arc" order="34.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="us-gaap_RepaymentsOfNotesPayable_7648" />
    <link:definitionArc xlink:type="arc" order="29.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="us-gaap_RepaymentsOfDebt_8804" />
    <link:definitionArc xlink:type="arc" order="14.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dmiiu_RelatedPartiesDetailsTable_1307" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1321" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_RelatedPartyTransactionAxis_1314" xlink:to="us-gaap_RelatedPartyTransactionDomain_1315" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dmiiu_RelatedPartiesDetailsTable_1307" xlink:to="us-gaap_RelatedPartyTransactionAxis_1314" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis_1311" xlink:to="us-gaap_ClassOfStockDomain_1312" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare_7602" />
    <link:definitionArc xlink:type="arc" order="17.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dmiiu_RelatedPartiesDetailsTable_1307" xlink:to="us-gaap_CreditFacilityAxis_1325" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_CreditFacilityAxis_1325" xlink:to="us-gaap_CreditFacilityDomain_1326" />
    <link:definitionArc xlink:type="arc" order="27.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="us-gaap_GeneralAndAdministrativeExpense_1345" />
    <link:definitionArc xlink:type="arc" order="744.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="us-gaap_OtherExpenses_8911" />
    <link:definitionArc xlink:type="arc" order="39.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="us-gaap_IncreaseDecreaseInDueFromRelatedParties_7651" />
    <link:definitionArc xlink:type="arc" order="20.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="us-gaap_SaleOfStockPricePerShare_1338" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1308" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1309" />
    <link:definitionArc xlink:type="arc" order="33.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_WorkingCapital_7647" />
    <link:definitionArc xlink:type="arc" order="43.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_WorkingCapitalLoans_1354" />
    <link:definitionArc xlink:type="arc" order="16.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dmiiu_RelatedPartiesDetailsTable_1307" xlink:to="srt_RangeAxis_8845" />
    <link:definitionArc xlink:type="arc" order="26.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="us-gaap_AccruedLiabilitiesCurrentAndNoncurrent_1344" />
    <link:definitionArc xlink:type="arc" order="25.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="us-gaap_AdministrativeFeesExpense_1343" />
    <link:definitionArc xlink:type="arc" order="711.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_8873" />
    <link:definitionArc xlink:type="arc" order="742.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_ServiceFeesPerMonth_8908" />
    <link:definitionArc xlink:type="arc" order="743.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="dmiiu_ServiceFeesPerYear_8909" />
    <link:definitionArc xlink:type="arc" order="28.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="us-gaap_ShortTermBorrowings_1346" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dmiiu_RelatedPartiesDetailsTable_1307" xlink:to="us-gaap_StatementClassOfStockAxis_1311" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="us-gaap_StockIssuedDuringPeriodSharesNewIssues_1332" />
    <link:definitionArc xlink:type="arc" order="16.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1331" xlink:to="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationForfeited_1335" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dmiiu_RelatedPartiesDetailsTable_1307" xlink:to="us-gaap_SubsidiarySaleOfStockAxis_1308" />
    <link:definitionArc xlink:type="arc" order="18.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dmiiu_RelatedPartiesDetailsTable_1307" xlink:to="us-gaap_TypeOfArrangementAxis_7628" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1321" xlink:to="us-gaap_RelatedPartyDomain_1322" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_TypeOfArrangementAxis_7628" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember_7669_default" />
    <link:definitionArc xlink:type="arc" order="685.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="srt_RangeAxis_8845" xlink:to="srt_RangeMember_8846_default" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_RelatedPartyTransactionAxis_1314" xlink:to="us-gaap_RelatedPartyTransactionDomain_1315_default" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementClassOfStockAxis_1311" xlink:to="us-gaap_ClassOfStockDomain_1312_default" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_CreditFacilityAxis_1325" xlink:to="us-gaap_CreditFacilityDomain_1326_default" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1308" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1309_default" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1321" xlink:to="us-gaap_RelatedPartyDomain_1322_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://dmaacorp.com/20260630/role/ShareholdersDeficitDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember_1379" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis_1377" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityNoteAbstract" xlink:label="us-gaap_StockholdersEquityNoteAbstract_1375" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_PercentageOfOutstandingOrdinaryShares" xlink:label="dmiiu_PercentageOfOutstandingOrdinaryShares_1392" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_ShareholdersDeficitDetailsTable" xlink:label="dmiiu_ShareholdersDeficitDetailsTable_1376" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems" xlink:label="us-gaap_ClassOfStockLineItems_1380" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_PercentageOfIssuedOrdinaryShares" xlink:label="dmiiu_PercentageOfIssuedOrdinaryShares_1391" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesIssued" xlink:label="us-gaap_CommonStockSharesIssued_1388" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TemporaryEquitySharesOutstanding" xlink:label="us-gaap_TemporaryEquitySharesOutstanding_1390" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="us-gaap_CommonStockSharesAuthorized_1385" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_1386" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="us-gaap_CommonStockSharesOutstanding_1389" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockVotingRights" xlink:label="us-gaap_CommonStockVotingRights_1387" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain_1378" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare_1382" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:label="us-gaap_PreferredStockSharesAuthorized_1381" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesIssued" xlink:label="us-gaap_PreferredStockSharesIssued_1383" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:label="us-gaap_PreferredStockSharesOutstanding_1384" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain_1378_default" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain_1378" xlink:to="us-gaap_CommonStockMember_1379" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dmiiu_ShareholdersDeficitDetailsTable_1376" xlink:to="us-gaap_StatementEquityComponentsAxis_1377" />
    <link:definitionArc xlink:type="arc" order="21.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1380" xlink:to="dmiiu_PercentageOfOutstandingOrdinaryShares_1392" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ClassOfStockLineItems_1380" xlink:to="dmiiu_ShareholdersDeficitDetailsTable_1376" />
    <link:definitionArc xlink:type="arc" order="20.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1380" xlink:to="dmiiu_PercentageOfIssuedOrdinaryShares_1391" />
    <link:definitionArc xlink:type="arc" order="17.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1380" xlink:to="us-gaap_CommonStockSharesIssued_1388" />
    <link:definitionArc xlink:type="arc" order="19.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1380" xlink:to="us-gaap_TemporaryEquitySharesOutstanding_1390" />
    <link:definitionArc xlink:type="arc" order="14.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1380" xlink:to="us-gaap_CommonStockSharesAuthorized_1385" />
    <link:definitionArc xlink:type="arc" order="15.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1380" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare_1386" />
    <link:definitionArc xlink:type="arc" order="18.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1380" xlink:to="us-gaap_CommonStockSharesOutstanding_1389" />
    <link:definitionArc xlink:type="arc" order="16.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1380" xlink:to="us-gaap_CommonStockVotingRights_1387" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementEquityComponentsAxis_1377" xlink:to="us-gaap_EquityComponentDomain_1378" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1380" xlink:to="us-gaap_PreferredStockParOrStatedValuePerShare_1382" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1380" xlink:to="us-gaap_PreferredStockSharesAuthorized_1381" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1380" xlink:to="us-gaap_PreferredStockSharesIssued_1383" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1380" xlink:to="us-gaap_PreferredStockSharesOutstanding_1384" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementEquityComponentsAxis_1377" xlink:to="us-gaap_EquityComponentDomain_1378_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://dmaacorp.com/20260630/role/FairValueMeasurementsScheduleofFairValueHierarchyoftheValuationInputsDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="us-gaap_FairValueInputsLevel1Member_1211" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_ScheduleOfFairValueHierarchyOfTheValuationInputsAbstract" xlink:label="dmiiu_ScheduleOfFairValueHierarchyOfTheValuationInputsAbstract_1208" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsFairValueDisclosureAbstract" xlink:label="us-gaap_AssetsFairValueDisclosureAbstract_1214" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsHeldInTrust" xlink:label="us-gaap_AssetsHeldInTrust_1215" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis_1210" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_FairValueMeasurementsScheduleofFairValueHierarchyoftheValuationInputsDetailsTable" xlink:label="dmiiu_FairValueMeasurementsScheduleofFairValueHierarchyoftheValuationInputsDetailsTable_1209" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_FairValueMeasurementsScheduleofFairValueHierarchyoftheValuationInputsDetailsLineItems" xlink:label="dmiiu_FairValueMeasurementsScheduleofFairValueHierarchyoftheValuationInputsDetailsLineItems_1213" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_7665" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_7665_default" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_7665" xlink:to="us-gaap_FairValueInputsLevel1Member_1211" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dmiiu_FairValueMeasurementsScheduleofFairValueHierarchyoftheValuationInputsDetailsLineItems_1213" xlink:to="us-gaap_AssetsFairValueDisclosureAbstract_1214" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsFairValueDisclosureAbstract_1214" xlink:to="us-gaap_AssetsHeldInTrust_1215" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dmiiu_FairValueMeasurementsScheduleofFairValueHierarchyoftheValuationInputsDetailsTable_1209" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis_1210" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="dmiiu_FairValueMeasurementsScheduleofFairValueHierarchyoftheValuationInputsDetailsLineItems_1213" xlink:to="dmiiu_FairValueMeasurementsScheduleofFairValueHierarchyoftheValuationInputsDetailsTable_1209" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis_1210" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_7665" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis_1210" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_7665_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://dmaacorp.com/20260630/role/CommitmentsandContingenciesDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_UnderwritingAgreementMember" xlink:label="dmiiu_UnderwritingAgreementMember_1364" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember_1363" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IPOMember" xlink:label="us-gaap_IPOMember_1361" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OverAllotmentOptionMember" xlink:label="us-gaap_OverAllotmentOptionMember_1360" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_1358" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesIssuedPricePerShare" xlink:label="us-gaap_SharesIssuedPricePerShare_1371" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_CashUnderwritingDiscount" xlink:label="dmiiu_CashUnderwritingDiscount_1368" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_DeferredFeeAmount" xlink:label="dmiiu_DeferredFeeAmount_1373" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_DeferredFeesPerUnit" xlink:label="dmiiu_DeferredFeesPerUnit_1370" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_ProceedsFromOverAllotmentOption" xlink:label="dmiiu_ProceedsFromOverAllotmentOption_1372" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_UnderwritingAgreementOptionPeriod" xlink:label="dmiiu_UnderwritingAgreementOptionPeriod_1366" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_UnitsIssuedDuringPeriodSharesNewIssues" xlink:label="dmiiu_UnitsIssuedDuringPeriodSharesNewIssues_1367" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract_1356" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitmentsLineItems" xlink:label="us-gaap_OtherCommitmentsLineItems_1365" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitmentsTable" xlink:label="us-gaap_OtherCommitmentsTable_1357" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForUnderwritingExpense" xlink:label="us-gaap_PaymentsForUnderwritingExpense_1369" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="us-gaap_TypeOfArrangementAxis_1362" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1359" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember_1363_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1359_default" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ArrangementsAndNonarrangementTransactionsMember_1363" xlink:to="dmiiu_UnderwritingAgreementMember_1364" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_TypeOfArrangementAxis_1362" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember_1363" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1359" xlink:to="us-gaap_IPOMember_1361" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1359" xlink:to="us-gaap_OverAllotmentOptionMember_1360" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_OtherCommitmentsTable_1357" xlink:to="us-gaap_SubsidiarySaleOfStockAxis_1358" />
    <link:definitionArc xlink:type="arc" order="15.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems_1365" xlink:to="us-gaap_SharesIssuedPricePerShare_1371" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems_1365" xlink:to="dmiiu_CashUnderwritingDiscount_1368" />
    <link:definitionArc xlink:type="arc" order="17.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems_1365" xlink:to="dmiiu_DeferredFeeAmount_1373" />
    <link:definitionArc xlink:type="arc" order="14.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems_1365" xlink:to="dmiiu_DeferredFeesPerUnit_1370" />
    <link:definitionArc xlink:type="arc" order="16.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems_1365" xlink:to="dmiiu_ProceedsFromOverAllotmentOption_1372" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems_1365" xlink:to="dmiiu_UnderwritingAgreementOptionPeriod_1366" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems_1365" xlink:to="dmiiu_UnitsIssuedDuringPeriodSharesNewIssues_1367" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_OtherCommitmentsLineItems_1365" xlink:to="us-gaap_OtherCommitmentsTable_1357" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems_1365" xlink:to="us-gaap_PaymentsForUnderwritingExpense_1369" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_OtherCommitmentsTable_1357" xlink:to="us-gaap_TypeOfArrangementAxis_1362" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1358" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1359" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_TypeOfArrangementAxis_1362" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember_1363_default" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1358" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1359_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://dmaacorp.com/20260630/role/Cover" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember_1411" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_UnitsMember" xlink:label="dmiiu_UnitsMember_1410" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_RightMember" xlink:label="dmiiu_RightMember_1412" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityRegistrantName" xlink:label="dei_EntityRegistrantName_7525" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityInteractiveDataCurrent" xlink:label="dei_EntityInteractiveDataCurrent_1699" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityIncorporationStateCountryCode" xlink:label="dei_EntityIncorporationStateCountryCode_7530" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityFilerCategory" xlink:label="dei_EntityFilerCategory_7557" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_AmendmentFlag" xlink:label="dei_AmendmentFlag_1701" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CityAreaCode" xlink:label="dei_CityAreaCode_7540" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CoverAbstract" xlink:label="dei_CoverAbstract_1407" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CurrentFiscalYearEndDate" xlink:label="dei_CurrentFiscalYearEndDate_8799" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="dei_DocumentFiscalPeriodFocus_1704" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentFiscalYearFocus" xlink:label="dei_DocumentFiscalYearFocus_1703" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentInformationLineItems" xlink:label="dei_DocumentInformationLineItems_1416" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentInformationTable" xlink:label="dei_DocumentInformationTable_1413" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentPeriodEndDate" xlink:label="dei_DocumentPeriodEndDate_1702" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentQuarterlyReport" xlink:label="dei_DocumentQuarterlyReport_8821" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityTaxIdentificationNumber" xlink:label="dei_EntityTaxIdentificationNumber_7526" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntitySmallBusiness" xlink:label="dei_EntitySmallBusiness_7558" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityShellCompany" xlink:label="dei_EntityShellCompany_7556" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis_1408" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityFileNumber" xlink:label="dei_EntityFileNumber_7523" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityExTransitionPeriod" xlink:label="dei_EntityExTransitionPeriod_7566" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityEmergingGrowthCompany" xlink:label="dei_EntityEmergingGrowthCompany_7563" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCurrentReportingStatus" xlink:label="dei_EntityCurrentReportingStatus_7555" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="dei_EntityCommonStockSharesOutstanding_7570" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCentralIndexKey" xlink:label="dei_EntityCentralIndexKey_7524" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressStateOrProvince" xlink:label="dei_EntityAddressStateOrProvince_7534" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressPostalZipCode" xlink:label="dei_EntityAddressPostalZipCode_7536" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressCityOrTown" xlink:label="dei_EntityAddressCityOrTown_7533" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressAddressLine2" xlink:label="dei_EntityAddressAddressLine2_7532" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressAddressLine1" xlink:label="dei_EntityAddressAddressLine1_7531" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentType" xlink:label="dei_DocumentType_1417" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentTransitionReport" xlink:label="dei_DocumentTransitionReport_1697" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1409" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_TradingSymbol" xlink:label="dei_TradingSymbol_7544" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_SecurityExchangeName" xlink:label="dei_SecurityExchangeName_7545" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_Security12bTitle" xlink:label="dei_Security12bTitle_7543" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LocalPhoneNumber" xlink:label="dei_LocalPhoneNumber_7541" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1409_default" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1409" xlink:to="us-gaap_CommonStockMember_1411" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1409" xlink:to="dmiiu_UnitsMember_1410" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1409" xlink:to="dmiiu_RightMember_1412" />
    <link:definitionArc xlink:type="arc" order="21.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_EntityRegistrantName_7525" />
    <link:definitionArc xlink:type="arc" order="38.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_EntityInteractiveDataCurrent_1699" />
    <link:definitionArc xlink:type="arc" order="23.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_EntityIncorporationStateCountryCode_7530" />
    <link:definitionArc xlink:type="arc" order="39.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_EntityFilerCategory_7557" />
    <link:definitionArc xlink:type="arc" order="18.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_AmendmentFlag_1701" />
    <link:definitionArc xlink:type="arc" order="30.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_CityAreaCode_7540" />
    <link:definitionArc xlink:type="arc" order="17.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_CurrentFiscalYearEndDate_8799" />
    <link:definitionArc xlink:type="arc" order="16.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_DocumentFiscalPeriodFocus_1704" />
    <link:definitionArc xlink:type="arc" order="15.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_DocumentFiscalYearFocus_1703" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_DocumentInformationTable_1413" />
    <link:definitionArc xlink:type="arc" order="14.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_DocumentPeriodEndDate_1702" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_DocumentQuarterlyReport_8821" />
    <link:definitionArc xlink:type="arc" order="24.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_EntityTaxIdentificationNumber_7526" />
    <link:definitionArc xlink:type="arc" order="40.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_EntitySmallBusiness_7558" />
    <link:definitionArc xlink:type="arc" order="45.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_EntityShellCompany_7556" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dei_DocumentInformationTable_1413" xlink:to="us-gaap_StatementClassOfStockAxis_1408" />
    <link:definitionArc xlink:type="arc" order="20.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_EntityFileNumber_7523" />
    <link:definitionArc xlink:type="arc" order="42.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_EntityExTransitionPeriod_7566" />
    <link:definitionArc xlink:type="arc" order="41.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_EntityEmergingGrowthCompany_7563" />
    <link:definitionArc xlink:type="arc" order="37.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_EntityCurrentReportingStatus_7555" />
    <link:definitionArc xlink:type="arc" order="47.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_EntityCommonStockSharesOutstanding_7570" />
    <link:definitionArc xlink:type="arc" order="22.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_EntityCentralIndexKey_7524" />
    <link:definitionArc xlink:type="arc" order="28.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_EntityAddressStateOrProvince_7534" />
    <link:definitionArc xlink:type="arc" order="29.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_EntityAddressPostalZipCode_7536" />
    <link:definitionArc xlink:type="arc" order="27.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_EntityAddressCityOrTown_7533" />
    <link:definitionArc xlink:type="arc" order="26.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_EntityAddressAddressLine2_7532" />
    <link:definitionArc xlink:type="arc" order="25.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_EntityAddressAddressLine1_7531" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_DocumentType_1417" />
    <link:definitionArc xlink:type="arc" order="19.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_DocumentTransitionReport_1697" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis_1408" xlink:to="us-gaap_ClassOfStockDomain_1409" />
    <link:definitionArc xlink:type="arc" order="33.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_TradingSymbol_7544" />
    <link:definitionArc xlink:type="arc" order="34.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_SecurityExchangeName_7545" />
    <link:definitionArc xlink:type="arc" order="32.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_Security12bTitle_7543" />
    <link:definitionArc xlink:type="arc" order="31.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1416" xlink:to="dei_LocalPhoneNumber_7541" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementClassOfStockAxis_1408" xlink:to="us-gaap_ClassOfStockDomain_1409_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://dmaacorp.com/20260630/role/SegmentInformationDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_ReportableSegmentMember" xlink:label="dmiiu_ReportableSegmentMember_8915" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain" xlink:label="us-gaap_SegmentDomain_8914" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_NumberOfReportableSegmentsNotDisclosedFlag" xlink:label="dmiiu_NumberOfReportableSegmentsNotDisclosedFlag_8917" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="us-gaap_StatementBusinessSegmentsAxis_8913" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NumberOfOperatingSegments" xlink:label="us-gaap_NumberOfOperatingSegments_1405" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_7701" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingAbstract" xlink:label="us-gaap_SegmentReportingAbstract_1402" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingCodmIndividualTitleAndPositionOrGroupOrCommitteeNameExtensibleEnumeration" xlink:label="us-gaap_SegmentReportingCodmIndividualTitleAndPositionOrGroupOrCommitteeNameExtensibleEnumeration_1404" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingCodmProfitLossMeasureHowUsedDescription" xlink:label="us-gaap_SegmentReportingCodmProfitLossMeasureHowUsedDescription_1403" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="us-gaap_SegmentReportingInformationLineItems_7705" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain" xlink:label="us-gaap_SegmentDomain_8914_default" />
    <link:definitionArc xlink:type="arc" order="748.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentDomain_8914" xlink:to="dmiiu_ReportableSegmentMember_8915" />
    <link:definitionArc xlink:type="arc" order="747.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementBusinessSegmentsAxis_8913" xlink:to="us-gaap_SegmentDomain_8914" />
    <link:definitionArc xlink:type="arc" order="750.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems_7705" xlink:to="dmiiu_NumberOfReportableSegmentsNotDisclosedFlag_8917" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_7701" xlink:to="us-gaap_StatementBusinessSegmentsAxis_8913" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems_7705" xlink:to="us-gaap_NumberOfOperatingSegments_1405" />
    <link:definitionArc xlink:type="arc" order="559.00000" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_SegmentReportingInformationLineItems_7705" xlink:to="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_7701" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems_7705" xlink:to="us-gaap_SegmentReportingCodmIndividualTitleAndPositionOrGroupOrCommitteeNameExtensibleEnumeration_1404" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems_7705" xlink:to="us-gaap_SegmentReportingCodmProfitLossMeasureHowUsedDescription_1403" />
    <link:definitionArc xlink:type="arc" order="747.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementBusinessSegmentsAxis_8913" xlink:to="us-gaap_SegmentDomain_8914_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://dmaacorp.com/20260630/role/StatementsofOperationsUnaudited" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_NonRedeemableOrdinaryShareMember" xlink:label="dmiiu_NonRedeemableOrdinaryShareMember_1052" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_RedeemableOrdinaryShareMember" xlink:label="dmiiu_RedeemableOrdinaryShareMember_1051" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1050" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable_1048" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_7559" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss_7550" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis_1049" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems_7537" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonoperatingIncomeExpense" xlink:label="us-gaap_NonoperatingIncomeExpense_7549" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonoperatingIncomeExpenseAbstract" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract_7546" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpenses" xlink:label="us-gaap_OperatingExpenses_7542" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpensesAbstract" xlink:label="us-gaap_OperatingExpensesAbstract_7538" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss_7541" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForDoubtfulAccounts" xlink:label="us-gaap_ProvisionForDoubtfulAccounts_7564" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasic" xlink:label="us-gaap_EarningsPerShareBasic_7561" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="us-gaap_EarningsPerShareDiluted_7562" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="us-gaap_GeneralAndAdministrativeExpense_7539" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeStatementAbstract" xlink:label="us-gaap_IncomeStatementAbstract_1047" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIncomeInterest" xlink:label="us-gaap_InvestmentIncomeInterest_7547" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_7551" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1050_default" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1050" xlink:to="dmiiu_NonRedeemableOrdinaryShareMember_1052" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1050" xlink:to="dmiiu_RedeemableOrdinaryShareMember_1051" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis_1049" xlink:to="us-gaap_ClassOfStockDomain_1050" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_StatementLineItems_7537" xlink:to="us-gaap_StatementTable_1048" />
    <link:definitionArc xlink:type="arc" order="475.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_7537" xlink:to="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_7559" />
    <link:definitionArc xlink:type="arc" order="466.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_7537" xlink:to="us-gaap_NetIncomeLoss_7550" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable_1048" xlink:to="us-gaap_StatementClassOfStockAxis_1049" />
    <link:definitionArc xlink:type="arc" order="14.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract_7546" xlink:to="us-gaap_NonoperatingIncomeExpense_7549" />
    <link:definitionArc xlink:type="arc" order="462.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_7537" xlink:to="us-gaap_NonoperatingIncomeExpenseAbstract_7546" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OperatingExpensesAbstract_7538" xlink:to="us-gaap_OperatingExpenses_7542" />
    <link:definitionArc xlink:type="arc" order="455.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_7537" xlink:to="us-gaap_OperatingExpensesAbstract_7538" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OperatingExpensesAbstract_7538" xlink:to="us-gaap_OperatingIncomeLoss_7541" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract_7546" xlink:to="us-gaap_ProvisionForDoubtfulAccounts_7564" />
    <link:definitionArc xlink:type="arc" order="477.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_7537" xlink:to="us-gaap_EarningsPerShareBasic_7561" />
    <link:definitionArc xlink:type="arc" order="478.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_7537" xlink:to="us-gaap_EarningsPerShareDiluted_7562" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OperatingExpensesAbstract_7538" xlink:to="us-gaap_GeneralAndAdministrativeExpense_7539" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract_7546" xlink:to="us-gaap_InvestmentIncomeInterest_7547" />
    <link:definitionArc xlink:type="arc" order="467.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_7537" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_7551" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementClassOfStockAxis_1049" xlink:to="us-gaap_ClassOfStockDomain_1050_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://dmaacorp.com/20260630/role/DescriptionofOrganizationBusinessOperationsandGoingConcernDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_TrustAccountMember" xlink:label="dmiiu_TrustAccountMember_8879" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_CantorMember" xlink:label="dmiiu_CantorMember_1251" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IPOMember" xlink:label="us-gaap_IPOMember_1242" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PrivatePlacementMember" xlink:label="us-gaap_PrivatePlacementMember_1243" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OverAllotmentOptionMember" xlink:label="us-gaap_OverAllotmentOptionMember_1244" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_SponsorMember" xlink:label="dmiiu_SponsorMember_1250" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_PublicSharesMember" xlink:label="dmiiu_PublicSharesMember_1247" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_DeferredUnderwritingFeesPayable" xlink:label="dmiiu_DeferredUnderwritingFeesPayable_1265" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_MaximumNetInterestToPayDissolutionExpenses" xlink:label="dmiiu_MaximumNetInterestToPayDissolutionExpenses_1270" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_OtherOfferingCosts" xlink:label="dmiiu_OtherOfferingCosts_1266" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_CashUnderwritingFees" xlink:label="dmiiu_CashUnderwritingFees_1264" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_ConditionForFutureBusinessCombinationThresholdPercentageOwnership" xlink:label="dmiiu_ConditionForFutureBusinessCombinationThresholdPercentageOwnership_1259" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_DescriptionofOrganizationandBusinessOperationsDetailsTable" xlink:label="dmiiu_DescriptionofOrganizationandBusinessOperationsDetailsTable_1239" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_TransactionCosts" xlink:label="dmiiu_TransactionCosts_1263" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_MaturityPeriodForGovernmentTreasuryObligation" xlink:label="dmiiu_MaturityPeriodForGovernmentTreasuryObligation_1261" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_PercentageObligationToRedeemPublicSharesIfEntityDoesNotCompleteBusinessCombination" xlink:label="dmiiu_PercentageObligationToRedeemPublicSharesIfEntityDoesNotCompleteBusinessCombination_1262" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_UnitsIssuedDuringPeriodSharesNewIssues" xlink:label="dmiiu_UnitsIssuedDuringPeriodSharesNewIssues_1254" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityIncorporationDateOfIncorporation" xlink:label="dei_EntityIncorporationDateOfIncorporation_1253" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_WorkingCapitalDeficit" xlink:label="dmiiu_WorkingCapitalDeficit_1272" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_1271" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1246" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_ConditionForFutureBusinessCombinationUseOfProceedsPercentage" xlink:label="dmiiu_ConditionForFutureBusinessCombinationUseOfProceedsPercentage_1258" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockLineItems" xlink:label="us-gaap_SubsidiarySaleOfStockLineItems_1252" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceInitialPublicOffering" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering_1256" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfPrivatePlacement" xlink:label="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_1257" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1248" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1241" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_1240" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis_1245" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesIssuedPricePerShare" xlink:label="us-gaap_SharesIssuedPricePerShare_1255" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain_1249" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOrSaleOfEquity" xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity_1260" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_1238" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_RedemptionLimitPercentageWithoutPriorConsent" xlink:label="dmiiu_RedemptionLimitPercentageWithoutPriorConsent_1267" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_PublicOfferingPricePerUnit" xlink:label="dmiiu_PublicOfferingPricePerUnit_1268" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_PeriodFromClosingOfPublicOfferingToCompleteBusinessCombination" xlink:label="dmiiu_PeriodFromClosingOfPublicOfferingToCompleteBusinessCombination_1269" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1246_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1241_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain_1249_default" />
    <link:definitionArc xlink:type="arc" order="717.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain_1249" xlink:to="dmiiu_TrustAccountMember_8879" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain_1249" xlink:to="dmiiu_CantorMember_1251" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1241" xlink:to="us-gaap_IPOMember_1242" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1241" xlink:to="us-gaap_PrivatePlacementMember_1243" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1241" xlink:to="us-gaap_OverAllotmentOptionMember_1244" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain_1249" xlink:to="dmiiu_SponsorMember_1250" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1246" xlink:to="dmiiu_PublicSharesMember_1247" />
    <link:definitionArc xlink:type="arc" order="22.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1252" xlink:to="dmiiu_DeferredUnderwritingFeesPayable_1265" />
    <link:definitionArc xlink:type="arc" order="27.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1252" xlink:to="dmiiu_MaximumNetInterestToPayDissolutionExpenses_1270" />
    <link:definitionArc xlink:type="arc" order="23.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1252" xlink:to="dmiiu_OtherOfferingCosts_1266" />
    <link:definitionArc xlink:type="arc" order="21.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1252" xlink:to="dmiiu_CashUnderwritingFees_1264" />
    <link:definitionArc xlink:type="arc" order="16.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1252" xlink:to="dmiiu_ConditionForFutureBusinessCombinationThresholdPercentageOwnership_1259" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1252" xlink:to="dmiiu_DescriptionofOrganizationandBusinessOperationsDetailsTable_1239" />
    <link:definitionArc xlink:type="arc" order="20.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1252" xlink:to="dmiiu_TransactionCosts_1263" />
    <link:definitionArc xlink:type="arc" order="18.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1252" xlink:to="dmiiu_MaturityPeriodForGovernmentTreasuryObligation_1261" />
    <link:definitionArc xlink:type="arc" order="19.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1252" xlink:to="dmiiu_PercentageObligationToRedeemPublicSharesIfEntityDoesNotCompleteBusinessCombination_1262" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1252" xlink:to="dmiiu_UnitsIssuedDuringPeriodSharesNewIssues_1254" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1252" xlink:to="dei_EntityIncorporationDateOfIncorporation_1253" />
    <link:definitionArc xlink:type="arc" order="29.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1252" xlink:to="dmiiu_WorkingCapitalDeficit_1272" />
    <link:definitionArc xlink:type="arc" order="28.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1252" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_1271" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis_1245" xlink:to="us-gaap_ClassOfStockDomain_1246" />
    <link:definitionArc xlink:type="arc" order="15.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1252" xlink:to="dmiiu_ConditionForFutureBusinessCombinationUseOfProceedsPercentage_1258" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1252" xlink:to="us-gaap_ProceedsFromIssuanceInitialPublicOffering_1256" />
    <link:definitionArc xlink:type="arc" order="14.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1252" xlink:to="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_1257" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dmiiu_DescriptionofOrganizationandBusinessOperationsDetailsTable_1239" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1248" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1240" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1241" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dmiiu_DescriptionofOrganizationandBusinessOperationsDetailsTable_1239" xlink:to="us-gaap_SubsidiarySaleOfStockAxis_1240" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dmiiu_DescriptionofOrganizationandBusinessOperationsDetailsTable_1239" xlink:to="us-gaap_StatementClassOfStockAxis_1245" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1252" xlink:to="us-gaap_SharesIssuedPricePerShare_1255" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1248" xlink:to="us-gaap_RelatedPartyDomain_1249" />
    <link:definitionArc xlink:type="arc" order="17.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1252" xlink:to="us-gaap_ProceedsFromIssuanceOrSaleOfEquity_1260" />
    <link:definitionArc xlink:type="arc" order="24.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1252" xlink:to="dmiiu_RedemptionLimitPercentageWithoutPriorConsent_1267" />
    <link:definitionArc xlink:type="arc" order="25.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1252" xlink:to="dmiiu_PublicOfferingPricePerUnit_1268" />
    <link:definitionArc xlink:type="arc" order="26.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1252" xlink:to="dmiiu_PeriodFromClosingOfPublicOfferingToCompleteBusinessCombination_1269" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementClassOfStockAxis_1245" xlink:to="us-gaap_ClassOfStockDomain_1246_default" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1240" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1241_default" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1248" xlink:to="us-gaap_RelatedPartyDomain_1249_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://dmaacorp.com/20260630/role/PrivatePlacementDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_CantorMember" xlink:label="dmiiu_CantorMember_1299" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_SponsorMember" xlink:label="dmiiu_SponsorMember_1298" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PrivatePlacementMember" xlink:label="us-gaap_PrivatePlacementMember_1295" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfPrivatePlacement" xlink:label="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_1303" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_7662" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesIssuedPricePerShare" xlink:label="us-gaap_SharesIssuedPricePerShare_1302" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_1294" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems" xlink:label="us-gaap_ClassOfStockLineItems_1300" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_PrivatePlacementDetailsTable" xlink:label="dmiiu_PrivatePlacementDetailsTable_1293" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_UnitsIssuedDuringPeriodSharesNewIssue" xlink:label="dmiiu_UnitsIssuedDuringPeriodSharesNewIssue_1301" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_UnitsIssuedDuringPeriodSharesNewIssues" xlink:label="dmiiu_UnitsIssuedDuringPeriodSharesNewIssues_1304" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDisclosuresAbstract" xlink:label="us-gaap_ClassOfStockDisclosuresAbstract_1292" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionDomain" xlink:label="us-gaap_RelatedPartyTransactionDomain_1297" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionAxis" xlink:label="us-gaap_RelatedPartyTransactionAxis_1296" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_7662_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionDomain" xlink:label="us-gaap_RelatedPartyTransactionDomain_1297_default" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionDomain_1297" xlink:to="dmiiu_CantorMember_1299" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionDomain_1297" xlink:to="dmiiu_SponsorMember_1298" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_7662" xlink:to="us-gaap_PrivatePlacementMember_1295" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1300" xlink:to="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_1303" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1294" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_7662" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1300" xlink:to="us-gaap_SharesIssuedPricePerShare_1302" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dmiiu_PrivatePlacementDetailsTable_1293" xlink:to="us-gaap_SubsidiarySaleOfStockAxis_1294" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ClassOfStockLineItems_1300" xlink:to="dmiiu_PrivatePlacementDetailsTable_1293" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1300" xlink:to="dmiiu_UnitsIssuedDuringPeriodSharesNewIssue_1301" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1300" xlink:to="dmiiu_UnitsIssuedDuringPeriodSharesNewIssues_1304" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_RelatedPartyTransactionAxis_1296" xlink:to="us-gaap_RelatedPartyTransactionDomain_1297" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dmiiu_PrivatePlacementDetailsTable_1293" xlink:to="us-gaap_RelatedPartyTransactionAxis_1296" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1294" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_7662_default" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_RelatedPartyTransactionAxis_1296" xlink:to="us-gaap_RelatedPartyTransactionDomain_1297_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://dmaacorp.com/20260630/role/StatementsofOperationsUnauditedParentheticals" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_FounderSharesMember" xlink:label="dmiiu_FounderSharesMember_7635" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember_7638" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OverAllotmentOptionMember" xlink:label="us-gaap_OverAllotmentOptionMember_7634" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain_7637" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeStatementAbstract" xlink:label="us-gaap_IncomeStatementAbstract_7630" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable_7631" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_7632" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems_7639" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis_7636" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_7633" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationForfeited" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationForfeited_8919" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain_7637_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_7633_default" />
    <link:definitionArc xlink:type="arc" order="522.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_7633" xlink:to="dmiiu_FounderSharesMember_7635" />
    <link:definitionArc xlink:type="arc" order="525.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain_7637" xlink:to="us-gaap_CommonStockMember_7638" />
    <link:definitionArc xlink:type="arc" order="521.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_7633" xlink:to="us-gaap_OverAllotmentOptionMember_7634" />
    <link:definitionArc xlink:type="arc" order="524.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementEquityComponentsAxis_7636" xlink:to="us-gaap_EquityComponentDomain_7637" />
    <link:definitionArc xlink:type="arc" order="518.00000" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_StatementLineItems_7639" xlink:to="us-gaap_StatementTable_7631" />
    <link:definitionArc xlink:type="arc" order="519.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable_7631" xlink:to="us-gaap_SubsidiarySaleOfStockAxis_7632" />
    <link:definitionArc xlink:type="arc" order="523.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable_7631" xlink:to="us-gaap_StatementEquityComponentsAxis_7636" />
    <link:definitionArc xlink:type="arc" order="520.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_7632" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_7633" />
    <link:definitionArc xlink:type="arc" order="752.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_7639" xlink:to="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationForfeited_8919" />
    <link:definitionArc xlink:type="arc" order="524.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementEquityComponentsAxis_7636" xlink:to="us-gaap_EquityComponentDomain_7637_default" />
    <link:definitionArc xlink:type="arc" order="520.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_7632" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_7633_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://dmaacorp.com/20260630/role/SummaryofSignificantAccountingPoliciesDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember_8833" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OverAllotmentOptionMember" xlink:label="us-gaap_OverAllotmentOptionMember_8830" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_ReserveForCurrentExpectedCreditLossesMember" xlink:label="dmiiu_ReserveForCurrentExpectedCreditLossesMember_8878" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PrivatePlacementMember" xlink:label="us-gaap_PrivatePlacementMember_8920" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ChangeInAccountingEstimateLineItems" xlink:label="us-gaap_ChangeInAccountingEstimateLineItems_8837" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLiabilities" xlink:label="us-gaap_DerivativeLiabilities_8834" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasic" xlink:label="us-gaap_EarningsPerShareBasic_8835" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="us-gaap_EarningsPerShareDiluted_8836" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain_8832" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_8829" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis_8831" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationForfeited" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationForfeited_1280" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnrecognizedTaxBenefits" xlink:label="us-gaap_UnrecognizedTaxBenefits_1277" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_NumberOfOrdinarySharesSubjectToForfeitures" xlink:label="dmiiu_NumberOfOrdinarySharesSubjectToForfeitures_8875" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_ProbabilityOfRepaymentAmount" xlink:label="dmiiu_ProbabilityOfRepaymentAmount_8818" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="us-gaap_AccountingPoliciesAbstract_1274" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsHeldInTrustNoncurrent" xlink:label="us-gaap_AssetsHeldInTrustNoncurrent_7603" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Cash" xlink:label="us-gaap_Cash_1275" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashFDICInsuredAmount" xlink:label="us-gaap_CashFDICInsuredAmount_1276" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_InitialBusinessCombinationOrToRedeemPercentage" xlink:label="dmiiu_InitialBusinessCombinationOrToRedeemPercentage_1279" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_SummaryOfSignificantAccountingPoliciesTable" xlink:label="dmiiu_SummaryOfSignificantAccountingPoliciesTable_8827" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashEquivalentsAtCarryingValue_7601" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForOtherCreditLosses" xlink:label="us-gaap_ProvisionForOtherCreditLosses_7604" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionAxis" xlink:label="us-gaap_RelatedPartyTransactionAxis_8876" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionDomain" xlink:label="us-gaap_RelatedPartyTransactionDomain_8877" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_1278" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_8828" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain_8832_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_8829_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionDomain" xlink:label="us-gaap_RelatedPartyTransactionDomain_8877_default" />
    <link:definitionArc xlink:type="arc" order="672.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain_8832" xlink:to="us-gaap_CommonStockMember_8833" />
    <link:definitionArc xlink:type="arc" order="669.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_8829" xlink:to="us-gaap_OverAllotmentOptionMember_8830" />
    <link:definitionArc xlink:type="arc" order="716.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionDomain_8877" xlink:to="dmiiu_ReserveForCurrentExpectedCreditLossesMember_8878" />
    <link:definitionArc xlink:type="arc" order="753.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_8829" xlink:to="us-gaap_PrivatePlacementMember_8920" />
    <link:definitionArc xlink:type="arc" order="21.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_8837" xlink:to="us-gaap_DerivativeLiabilities_8834" />
    <link:definitionArc xlink:type="arc" order="22.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_8837" xlink:to="us-gaap_EarningsPerShareBasic_8835" />
    <link:definitionArc xlink:type="arc" order="23.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_8837" xlink:to="us-gaap_EarningsPerShareDiluted_8836" />
    <link:definitionArc xlink:type="arc" order="671.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementEquityComponentsAxis_8831" xlink:to="us-gaap_EquityComponentDomain_8832" />
    <link:definitionArc xlink:type="arc" order="668.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_8828" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_8829" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dmiiu_SummaryOfSignificantAccountingPoliciesTable_8827" xlink:to="us-gaap_StatementEquityComponentsAxis_8831" />
    <link:definitionArc xlink:type="arc" order="16.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_8837" xlink:to="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationForfeited_1280" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_8837" xlink:to="us-gaap_UnrecognizedTaxBenefits_1277" />
    <link:definitionArc xlink:type="arc" order="713.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_8837" xlink:to="dmiiu_NumberOfOrdinarySharesSubjectToForfeitures_8875" />
    <link:definitionArc xlink:type="arc" order="19.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_8837" xlink:to="dmiiu_ProbabilityOfRepaymentAmount_8818" />
    <link:definitionArc xlink:type="arc" order="17.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_8837" xlink:to="us-gaap_AssetsHeldInTrustNoncurrent_7603" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_8837" xlink:to="us-gaap_Cash_1275" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_8837" xlink:to="us-gaap_CashFDICInsuredAmount_1276" />
    <link:definitionArc xlink:type="arc" order="15.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_8837" xlink:to="dmiiu_InitialBusinessCombinationOrToRedeemPercentage_1279" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_8837" xlink:to="dmiiu_SummaryOfSignificantAccountingPoliciesTable_8827" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_8837" xlink:to="us-gaap_CashEquivalentsAtCarryingValue_7601" />
    <link:definitionArc xlink:type="arc" order="18.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_8837" xlink:to="us-gaap_ProvisionForOtherCreditLosses_7604" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dmiiu_SummaryOfSignificantAccountingPoliciesTable_8827" xlink:to="us-gaap_RelatedPartyTransactionAxis_8876" />
    <link:definitionArc xlink:type="arc" order="715.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_RelatedPartyTransactionAxis_8876" xlink:to="us-gaap_RelatedPartyTransactionDomain_8877" />
    <link:definitionArc xlink:type="arc" order="14.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_8837" xlink:to="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_1278" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dmiiu_SummaryOfSignificantAccountingPoliciesTable_8827" xlink:to="us-gaap_SubsidiarySaleOfStockAxis_8828" />
    <link:definitionArc xlink:type="arc" order="671.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementEquityComponentsAxis_8831" xlink:to="us-gaap_EquityComponentDomain_8832_default" />
    <link:definitionArc xlink:type="arc" order="668.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_8828" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_8829_default" />
    <link:definitionArc xlink:type="arc" order="715.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_RelatedPartyTransactionAxis_8876" xlink:to="us-gaap_RelatedPartyTransactionDomain_8877_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://dmaacorp.com/20260630/role/StatementsofChangesInShareholdersDeficitUnaudited" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="us-gaap_AdditionalPaidInCapitalMember_1069" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember_1068" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsMember" xlink:label="us-gaap_RetainedEarningsMember_1070" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity_1073" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable_1066" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems_1072" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis_1067" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfStockholdersEquityAbstract" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract_1065" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_AdjustmentOfAdditionalPaidInCapitalAccretionAndRemeasurementForRedeemableOrdinarySharesToRedemptionAmount" xlink:label="dmiiu_AdjustmentOfAdditionalPaidInCapitalAccretionAndRemeasurementForRedeemableOrdinarySharesToRedemptionAmount_1079" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_CapitalContributionThroughCancellationOfAdministrativeSupportFee" xlink:label="dmiiu_CapitalContributionThroughCancellationOfAdministrativeSupportFee_8824" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain_1071" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss_1082" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesOutstanding" xlink:label="us-gaap_SharesOutstanding_1084" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain_1071_default" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain_1071" xlink:to="us-gaap_AdditionalPaidInCapitalMember_1069" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain_1071" xlink:to="us-gaap_CommonStockMember_1068" />
    <link:definitionArc xlink:type="arc" order="14.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain_1071" xlink:to="us-gaap_RetainedEarningsMember_1070" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1072" xlink:to="us-gaap_StockholdersEquity_1073" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_StatementLineItems_1072" xlink:to="us-gaap_StatementTable_1066" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable_1066" xlink:to="us-gaap_StatementEquityComponentsAxis_1067" />
    <link:definitionArc xlink:type="arc" order="14.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1072" xlink:to="dmiiu_AdjustmentOfAdditionalPaidInCapitalAccretionAndRemeasurementForRedeemableOrdinarySharesToRedemptionAmount_1079" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1072" xlink:to="dmiiu_CapitalContributionThroughCancellationOfAdministrativeSupportFee_8824" />
    <link:definitionArc xlink:type="arc" order="15.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementEquityComponentsAxis_1067" xlink:to="us-gaap_EquityComponentDomain_1071" />
    <link:definitionArc xlink:type="arc" order="15.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1072" xlink:to="us-gaap_NetIncomeLoss_1082" />
    <link:definitionArc xlink:type="arc" order="17.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1072" xlink:to="us-gaap_SharesOutstanding_1084" />
    <link:definitionArc xlink:type="arc" order="15.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementEquityComponentsAxis_1067" xlink:to="us-gaap_EquityComponentDomain_1071_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://dmaacorp.com/20260630/role/SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_NonRedeemableOrdinaryShareMember" xlink:label="dmiiu_NonRedeemableOrdinaryShareMember_1197" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_RedeemableOrdinaryShareMember" xlink:label="dmiiu_RedeemableOrdinaryShareMember_1196" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_1200" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_1205" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis_1195" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_1206" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_ScheduleOfBasicAndDilutedNetIncomePerOrdinaryShareAbstract" xlink:label="dmiiu_ScheduleOfBasicAndDilutedNetIncomePerOrdinaryShareAbstract_1193" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetailsLineItems" xlink:label="dmiiu_SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetailsLineItems_1198" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetailsTable" xlink:label="dmiiu_SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetailsTable_1194" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_7657" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasic" xlink:label="us-gaap_EarningsPerShareBasic_1203" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="us-gaap_EarningsPerShareDiluted_1204" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsAttributableToParentAbstract" xlink:label="us-gaap_IncomeLossFromContinuingOperationsAttributableToParentAbstract_1199" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_1201" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_1202" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_7657_default" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_7657" xlink:to="dmiiu_NonRedeemableOrdinaryShareMember_1197" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_7657" xlink:to="dmiiu_RedeemableOrdinaryShareMember_1196" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeLossFromContinuingOperationsAttributableToParentAbstract_1199" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_1200" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_1201" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_1205" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dmiiu_SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetailsTable_1194" xlink:to="us-gaap_StatementClassOfStockAxis_1195" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_1201" xlink:to="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_1206" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="dmiiu_SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetailsLineItems_1198" xlink:to="dmiiu_SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetailsTable_1194" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis_1195" xlink:to="us-gaap_ClassOfStockDomain_7657" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_1201" xlink:to="us-gaap_EarningsPerShareBasic_1203" />
    <link:definitionArc xlink:type="arc" order="14.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_1201" xlink:to="us-gaap_EarningsPerShareDiluted_1204" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dmiiu_SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetailsLineItems_1198" xlink:to="us-gaap_IncomeLossFromContinuingOperationsAttributableToParentAbstract_1199" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dmiiu_SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetailsLineItems_1198" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_1201" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_1201" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_1202" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementClassOfStockAxis_1195" xlink:to="us-gaap_ClassOfStockDomain_7657_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://dmaacorp.com/20260630/role/PromissoryNotesDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember_8904" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BridgeLoanMember" xlink:label="us-gaap_BridgeLoanMember_8905" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnsecuredDebt" xlink:label="us-gaap_UnsecuredDebt_8898" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_ConversionMarketPricePercentage" xlink:label="dmiiu_ConversionMarketPricePercentage_8906" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="us-gaap_TypeOfArrangementAxis_8903" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermDebtLineItems" xlink:label="us-gaap_ShortTermDebtLineItems_8895" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermBorrowings" xlink:label="us-gaap_ShortTermBorrowings_8896" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConvertibleNotesPayable" xlink:label="us-gaap_ConvertibleNotesPayable_8902" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_ConvertibleNotesFinancingAmount" xlink:label="dmiiu_ConvertibleNotesFinancingAmount_8899" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_ConversionPricePercentage" xlink:label="dmiiu_ConversionPricePercentage_8901" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_AlphaPromissoryNotesAbstract" xlink:label="dmiiu_AlphaPromissoryNotesAbstract_8887" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_AlphaPromissoryNotesTable" xlink:label="dmiiu_AlphaPromissoryNotesTable_8888" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember_8904_default" />
    <link:definitionArc xlink:type="arc" order="739.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_TypeOfArrangementAxis_8903" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember_8904" />
    <link:definitionArc xlink:type="arc" order="740.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ArrangementsAndNonarrangementTransactionsMember_8904" xlink:to="us-gaap_BridgeLoanMember_8905" />
    <link:definitionArc xlink:type="arc" order="733.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShortTermDebtLineItems_8895" xlink:to="us-gaap_UnsecuredDebt_8898" />
    <link:definitionArc xlink:type="arc" order="741.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShortTermDebtLineItems_8895" xlink:to="dmiiu_ConversionMarketPricePercentage_8906" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dmiiu_AlphaPromissoryNotesTable_8888" xlink:to="us-gaap_TypeOfArrangementAxis_8903" />
    <link:definitionArc xlink:type="arc" order="731.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShortTermDebtLineItems_8895" xlink:to="us-gaap_ShortTermBorrowings_8896" />
    <link:definitionArc xlink:type="arc" order="737.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShortTermDebtLineItems_8895" xlink:to="us-gaap_ConvertibleNotesPayable_8902" />
    <link:definitionArc xlink:type="arc" order="734.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShortTermDebtLineItems_8895" xlink:to="dmiiu_ConvertibleNotesFinancingAmount_8899" />
    <link:definitionArc xlink:type="arc" order="736.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShortTermDebtLineItems_8895" xlink:to="dmiiu_ConversionPricePercentage_8901" />
    <link:definitionArc xlink:type="arc" order="723.00000" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ShortTermDebtLineItems_8895" xlink:to="dmiiu_AlphaPromissoryNotesTable_8888" />
    <link:definitionArc xlink:type="arc" order="739.00000" priority="1" xbrldt:closed="true" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_TypeOfArrangementAxis_8903" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember_8904_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://dmaacorp.com/20260630/role/InitialPublicOfferingDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IPOMember" xlink:label="us-gaap_IPOMember_1285" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OverAllotmentOptionMember" xlink:label="us-gaap_OverAllotmentOptionMember_1286" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_InitialPublicOfferingDetailsTable" xlink:label="dmiiu_InitialPublicOfferingDetailsTable_1283" />
    <link:loc xlink:type="locator" xlink:href="dmiiu-20260630.xsd#dmiiu_UnitsIssuedDuringPeriodSharesNewIssues" xlink:label="dmiiu_UnitsIssuedDuringPeriodSharesNewIssues_1288" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDisclosuresAbstract" xlink:label="us-gaap_ClassOfStockDisclosuresAbstract_1282" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems" xlink:label="us-gaap_ClassOfStockLineItems_1287" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceInitialPublicOffering" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering_1290" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_7661" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesIssuedPricePerShare" xlink:label="us-gaap_SharesIssuedPricePerShare_1289" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_1284" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_7661_default" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_7661" xlink:to="us-gaap_IPOMember_1285" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_7661" xlink:to="us-gaap_OverAllotmentOptionMember_1286" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ClassOfStockLineItems_1287" xlink:to="dmiiu_InitialPublicOfferingDetailsTable_1283" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1287" xlink:to="dmiiu_UnitsIssuedDuringPeriodSharesNewIssues_1288" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1287" xlink:to="us-gaap_ProceedsFromIssuanceInitialPublicOffering_1290" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1284" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_7661" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1287" xlink:to="us-gaap_SharesIssuedPricePerShare_1289" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dmiiu_InitialPublicOfferingDetailsTable_1283" xlink:to="us-gaap_SubsidiarySaleOfStockAxis_1284" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1284" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_7661_default" />
  </link:definitionLink>
  <link:roleRef roleURI="http://fasb.org/srt/role/srt-eedm/ExtensibleEnumerationLists" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-roles-2026.xsd#eedm1" xlink:type="simple" />
  <link:definitionLink xlink:role="http://fasb.org/srt/role/srt-eedm/ExtensibleEnumerationLists" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="srt_TitleOfIndividualWithRelationshipToEntityDomain" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ChiefExecutiveOfficerMember" xlink:label="srt_ChiefExecutiveOfficerMember" />
    <link:definitionArc xlink:type="arc" order="0" priority="1" xbrldt:closed="true" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:to="srt_ChiefExecutiveOfficerMember" />
  </link:definitionLink>
</link:linkbase>
