Perfidy
Pronunciation : Per"fi*dy
Part of Speech : n.;
Etymology : [L. perfidia, fr. L. perfidus faithless; per (cf. Skr. para away) + fides faith: cf. F. perfidie. See Faith.]
Definition : Defn: 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.
pl. Perfidies.
Source : Webster's Unabridged Dictionary, 1913