The quality of being disloyal; faithlessness.
Something false; esp., a lie
An act of sexual unfaithfulness.
Deliberate breach of faith; calculated violation of trust; treachery:
Betrayal of trust, faith, or allegiance; perfidy, disloyalty, or treason
Find another word for perfidiousness. In this page you can discover 13 synonyms, antonyms, idiomatic expressions, and related words for perfidiousness, like: disloyalty, faithlessness, false-heartedness, falseness, falsity, infidelity, perfidy, traitorousness, treacherousness, treachery and unfaithfulness.