v.tr. 1 place (a person, one's country, etc.) in the hands or power of an enemy. 2 be disloyal to (another person, a person's trust, etc.). 3 reveal involuntarily or treacherously; be evidence of (his shaking hand betrayed his fear). 4 lead astray or into error. betrayal n. betrayer n.
[ ME f. obs. tray, ult. f. L tradere hand over ]