Betrayal, especially of a moral obligation
Willful betrayal of fidelity, confidence, or trust
No`aim had to pay for his perfidy with his life.
Nicholas was soon to have personal experience of the perfidy of Austria.
in the University library, Cambridge, strengthening her case by restating the perfidy of her accusers.
Soraij, a distinguished captain of the Arabic tribe of Tamim, who, with many pious Moslems, was scandalized by the government's perfidy in regard to the new converts.