The Oxford Thesaurus An A-Z Dictionary of Synonyms - betrayv.

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.