perfidy Meaning, Definition & Usage

  1. noun betrayal of a trust
    perfidiousness; treachery.
  2. noun an act of deliberate betrayal
    betrayal; treachery; treason.

WordNet

Per"fi*dy noun
Etymology
L. perfidia, fr. L. perfidus faithless; per (cf. Skr. para away) + fides faith: cf. F. perfidie. See Faith.
Wordforms
plural Perfidies
Definitions
  1. The act of violating faith or allegiance; violation of a promise or vow, or of trust reposed; faithlessness; teachery.
    The ambition and perfidy of tyrants. Macaulay.
    His perfidy to this sacred engagement. DeQuincey.

Webster 1913