Definition of perfidy in English:



  • Deceitfulness; untrustworthiness.

    • ‘They brook no compromise and instead repay those who would reach out to them with furious perfidy unless they show absolute fealty to every facet of the program.’
    • ‘Think of the valiant whistleblower inside a corporation or an agency who puts himself at risk to uncover criminal perfidy.’
    • ‘I have been accused of perfidy, malingering, duplicity, charlatanism and forty other words that I don't know the meaning of.’
    • ‘With possible political perfidy such a hot topic at Westminster, it is with perfect timing that the Lyceum and Citizens' theatres bring two of England's great plays of history and politics to the stage.’
    • ‘His book is a tale of cowardice, perfidy, hubris, idiocy and occasional heroism - told with considerable panache.’
    treachery, duplicity, deceit, perfidiousness, deceitfulness, disloyalty, infidelity, faithlessness, unfaithfulness, betrayal, treason, falseness, falsity, double-dealing, dishonesty, two-facedness, untrustworthiness, breach of trust
    false-heartedness, punic faith
    View synonyms


Late 16th century: via French from Latin perfidia, from perfidus treacherous based on per- to ill effect + fides faith.