Etymology First attested in English in 1628. Either inherited from an unattested Middle English borrowing from Anglo-Norman tant amount, from amunter, from tant (“as much”) amonter (“to amount to”) or borrowed in the early 17th century from Italian tanto montare (“to amount to as much”).
1
Equivalent in meaning or effect; amounting to the same thing in practical terms, even if being technically distinct.
Every moment might bring the British cruisers in sight,—two important expeditions had already been baffled in that way,—and the absolute certainty, known to all parties alike, that delay, under these circumstances, was tantamount to ruin; […]1853, Thomas De Quincey, “French Invasion of Ireland, and Second Rebellion”, in Autobiographic Sketches (De Quincey’s Works; I), London: James Hogg & Sons, →OCLC, page 270:
[…] expecting the woman to take her attacker into physical custody is tantamount to preventing the arrest. If she could handle him, she probably would not need to call the police in the first place.1981, Del Martin, Battered Wives, page 90:
3 more examples
In Bosnia, as in Rwanda, however, passive neutrality was tantamount to complicity with the perpetrators of “ethnic cleansing” and mass murder.2003 March 3, Philip Gourevitch, “The Optimist”, in The New Yorker:
Russia has said that it considers the weapons and other increased military aid that Western governments are sending to Ukraine tantamount to war, and has implied that it might strike NATO convoys.2022 March 16, Max Fisher, “As Russia Digs In, What’s the Risk of Nuclear War? ‘It’s Not Zero.’”, in The New York Times, →ISSN:
“Defendants’ representations to this Court that Mr. Musk is not running DOGE are tantamount to legal gaslighting,” CREW said.2025 March 30, Tierney Sneed, “Is DOGE actually an agency? The answer could have major ramifications”, in CNN:
tantamount
verb
Etymology First attested in English in 1628. Either inherited from an unattested Middle English borrowing from Anglo-Norman tant amount, from amunter, from tant (“as much”) amonter (“to amount to”) or borrowed in the early 17th century from Italian tanto montare (“to amount to as much”).
[…] and yet this will not tant’amount to an immediate Divine inſtitution for Deacons, and how can it then for Presbyters ?a. 1657, Jeremy Taylor, “Of the Sacred Order and Offices of Episcopacy, By Divine Institution, Apostolical Tradition, and Catholick Practice”, in Συμβολον Ἠθικο-Πολεμικον: or a Collection of Polemical and Moral Discourses, R. Royston, page 126:
tantamount
noun
Etymology First attested in English in 1628. Either inherited from an unattested Middle English borrowing from Anglo-Norman tant amount, from amunter, from tant (“as much”) amonter (“to amount to”) or borrowed in the early 17th century from Italian tanto montare (“to amount to as much”).
1
Obsolete Something which has the same value or amount (as something else). (attributive use passing into adjective, below)
For end thereof, not despondency but madness : for when Cossey understood that Hobday had called his wife a tantamount, he waited for him outside, and gave him what he called a pair of clippers over the ear.1977, Last Essays of Maurice Hewlett, page 42: