Pronunciation: (bi-trā'),[key] —v.t. 1. to deliver or expose to an enemy by treachery or disloyalty: Benedict Arnold betrayed his country. 2. to be unfaithful in guarding, maintaining, or fulfilling: to betray a trust. 3. to disappoint the hopes or expectations of; be disloyal to: to betray one's friends. 4. to reveal or disclose in violation of confidence: to betray a secret. 5. to reveal unconsciously (something one would preferably conceal): Her nervousness betrays her insecurity. 6. to show or exhibit; reveal; disclose: an unfeeling remark that betrays his lack of concern. 7. to deceive, misguide, or corrupt: a young lawyer betrayed by political ambitions into irreparable folly. 8. to seduce and desert.