v.
- act treacherously towards (one's country) by aiding the enemy.
▸be disloyal to or inform on.
- unintentionally reveal; be evidence of:
she drew a deep breath that betrayed her indignation.
Derivative
Etymology
ME: from be- + obs. tray ‘betray’, from OFr. trair, based on L. tradere ‘hand over’.