PERFIDY

treachery, betrayal, treason, perfidy

(noun) an act of deliberate betrayal

perfidy, perfidiousness, treachery

(noun) betrayal of a trust

Source: WordNet® 3.1

Etymology

Noun

perfidy (countable and uncountable, plural perfidies)

A state or act of violating faith or allegiance; violation of a promise or vow, or of trust

Synonyms: treachery, betrayal

(legal) Specifically, in warfare, an illegitimate act of deception, such as using symbols like the Red Cross or white flag to gain proximity to an enemy for purposes of attack.

A state or act of deceit.

Synonyms

• perfidiousness

Source: Wiktionary

Per"fi*dy, n.; pl. Perfidies. Etym: [L. perfidia, fr. L. perfidus faithless; per (cf. Skr. para away) + fides faith: cf. F. perfidie. See Faith.]

Definition: 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.

Source: Webster’s Unabridged Dictionary 1913 Edition