1 be or prove false or disloyal to, sell out, break faith with, let down, fail, inform on, Colloq sell down the river, Slang Brit shop:
He betrayed her to the enemy.
2 reveal, disclose, divulge, impart, tell; expose, lay bare:
She betrayed their hide-out to the police. He betrayed an unsuspected streak of cowardice.
3 lead astray, mislead, misguide, deceive, dupe, fool, hoodwink:
He has been betrayed by his own arrogance.