Perfidy /(pẽr"fĭ*dy̆)/
Per·fi·dy
Perfidy
n.
pl. Perfidies ((pẽr"fĭ*dĭz))
-
The act of violating faith or allegiance; violation of a promise or vow, or of trust reposed; faithlessness; treachery.
The ambition and perfidy of tyrants.
His perfidy to this sacred engagement.