from The American Heritage® Dictionary of the English Language, 4th Edition

  • adj. Of, relating to, or marked by perfidy; treacherous. See Synonyms at faithless.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • adj. Of, pertaining to, or representing perfidy; disloyal to what should command one's fidelity or allegiance.

from the GNU version of the Collaborative International Dictionary of English

  • adj. Guilty of perfidy; violating good faith or vows; false to trust or confidence reposed; teacherous; faithless.
  • adj. Involving, or characterized by, perfidy.

from The Century Dictionary and Cyclopedia

  • Faithless; basely treacherous; false-hearted.
  • Proceeding from or characterized by perfidy or base treachery; false: as, a perfidious act.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • adj. tending to betray; especially having a treacherous character as attributed to the Carthaginians by the Romans


Sorry, no etymologies found.


  • Then Miriam was furious, and complained to Minna about what she called her perfidious conduct; but Minna only laughed, and told her she could have Petrofsky instead. "

    John Thorndyke's Cases related by Christopher Jervis and edited by R. Austin Freeman

  • We wouldn't lie to you about the history of "perfidious" -- even though the word itself suggests deceitfulness.

    Merriam-Webster's Word of the Day

  • If soldiers are entitled to deal harshly with wounded enemy soldiers who might be engaged in perfidious acts, surely that entitlement can’t be contingent on holding a mini-trial right there to determine the matter.

    The Volokh Conspiracy » Phil Carter responds:

  • 'Your nation have well been called perfidious, Major Counsellor.

    A Modern Mercenary

  • From the end of 1796 the Venetian Senate secretly continued its armaments, and the whole conduct of that Government announced intentions which have been called perfidious, but the only object of which was to defeat intentions still more perfidious.

    The Memoirs of Napoleon

  • Jews and Judaism are characterized as the perfidious enemy of Islam and Israel becomes the Salmon Rushdie of the nations

    Conservapedia - Recent changes [en]

  • - where Jews and Judaism are characterized as the perfidious enemy of Islam, and Israel becomes the Salmon Rushdie of the nations.

    Conservapedia - Recent changes [en]

  • In truth, that prayer, which, in its first wording defined the Jews as "perfidious", that is "outside the faith" and blind, had already been "changed" but never abolished by John XXIII.

    Archive 2009-01-01

  • The kind of perfidious thing, of bad faith, that is characteristic of the imperialists because imperialists do not only kill there, here, everywhere, steal, plunder, lie, they are a personification of all that is immoral and bad in the world.


  • He wouldn't have found The Albion "perfidious" in the matter of "turtle and fine living," -- which was Mrs.R. 's description of the Pharisee.

    Punch, or the London Charivari, Volume 101, August 29, 1891


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  • Man in general seems a deceitful, tricky, dangerous, perfidious animal

    September 16, 2010

  • ...a perfidious cistern wakes me to stale

    potato crisps knocking the lintel...

    - Peter Reading, November 6th, from For the Municipality's Elderly, 1974

    June 22, 2008