Simple Definition of tantamount
: equal to something in value, meaning, or effect
Full Definition of tantamount
: equivalent in value, significance, or effect <a relationship tantamount to marriage>
Examples of tantamount
His statement was tantamount to an admission of guilt.
They see any criticism of the President as tantamount to treason.
Origin of tantamount
obsolete tantamount, noun, equivalent, from Anglo-French tant amunter to amount to as much
First Known Use: 1641
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