(adj) tending to betray; especially having a treacherous character as attributed to the Carthaginians by the Romans, Syn. perfidious, treacherous, Example:Punic faith; the perfidious Judas; the fiercest and most treacherous of foes; treacherous intrigues
The Collaborative International Dictionary of English (GCIDE) v.0.53 Collaborative International Dictionary (GCIDE)
a. [ L. perfidious. ] 1. Guilty of perfidy; violating good faith or vows; false to trust or confidence reposed; treacherous; faithless; as, a perfidious friend. Shak. [ 1913 Webster ]
2. Involving, or characterized by, perfidy. “Involved in this perfidious fraud.” Milton. [ 1913 Webster ]