[ pur-fi-dee ]
See synonyms for perfidy on
noun,plural per·fi·dies.
  1. deliberate breach of faith or trust; faithlessness; treachery: perfidy that goes unpunished.

  2. an act or instance of faithlessness or treachery.

Origin of perfidy

1585–95; <Latin perfidia faithlessness, equivalent to perfid(us) faithless, literally, through (i.e., beyond the limits of) faith (per-per- + fid(ēs) faith + -us adj. suffix) + -ia-y3

synonym study For perfidy

Words Nearby perfidy Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use perfidy in a sentence

  • Val's face turned red, for his perfidy rose up before him in its full extent of shame.

    Elster's Folly | Mrs. Henry Wood
  • She showed a consummate perfidy toward Diane de Poitiers, to which historians have not given due attention.

    Catherine de' Medici | Honore de Balzac
  • I shall experience all the degradation of a slave, but I will also practise a slave's perfidy and trickery.

  • They would not only refuse to give their assent to any such perfidy, but they would use their utmost endeavors to defeat it.

    Adrift on the Pacific | Edward S. Ellis

British Dictionary definitions for perfidy


/ (ˈpɜːfɪdɪ) /

nounplural -dies
  1. a perfidious act

Origin of perfidy

C16: from Latin perfidia, from perfidus faithless, from per beyond + fidēs faith

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