Perfidy means deceitfulness, treachery, or betrayal of trust.
It derives from the Latin perfidia — “faithlessness,” from perfidus (“false to one’s trust”).
Examples:
- The treaty was violated through an act of perfidy.
- She could not forgive his perfidy after so many years of loyalty.
Synonyms: treachery, betrayal, duplicity, deceit, disloyalty, treason.
Antonyms: faithfulness, loyalty, devotion, integrity.