equivalent, as in value, force, effect, or signification: His angry speech was tantamount to a declaration of war.

Origin of tantamount

1635–45; adj. use of obsolete noun: that which amounts to as much, itself noun use of obsolete v.: to amount to as much < Anglo-French tant amunter or Italian tanto montare to amount to as much. See tanto, amount
Can be confusedparamount tantamount

Synonyms for tantamount

See equal.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for tantamount

Contemporary Examples of tantamount

Historical Examples of tantamount

  • He did not answer her, for he could not speak at all; but his silence was tantamount to an admission.

    Cleo The Magnificent

    Louis Zangwill

  • He made a furious gesture, which was tantamount to sending her to the devil.

    His Masterpiece

    Emile Zola

  • It would be tantamount to acknowledging she was for sale but that he hadn't the price.

    The Paliser case

    Edgar Saltus

  • The average Republican regarded this message as tantamount to a declaration of war.

    Union and Democracy

    Allen Johnson

  • This would not do, said the colonel; it was tantamount to insubordination.

    Marion's Faith.

    Charles King

British Dictionary definitions for tantamount



(postpositive foll by to) as good (as); equivalent in effect (to)his statement was tantamount to an admission of guilt

Word Origin for tantamount

C17: basically from Anglo-French tant amunter to amount to as much, from tant so much + amunter to amount
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for tantamount

1640s, from verbal phrase tant amount "be equivalent" (1620s), from Anglo-French tant amunter "amount to as much" (late 13c.), from Old French tant "as much" (from Latin tantus, from tam "so") + amonter "amount to, go up" (see amount).

Online Etymology Dictionary, © 2010 Douglas Harper