betray
/bi-ˈtrā/
verb
to lead astray; especially : seduce
to deliver to an enemy by treachery
to fail or desert especially in time of need
reveal disclose divulge tell betray mean to make known what has been or should be concealed. reveal may apply to supernatural or inspired revelation of truths beyond the range of ordinary human vision or reason. disclose may imply a discovering but more often an imparting of information previously kept secret.
idiom
to fail show anything about what one is feeling or thinking
The expression on his face betrayed nothing.
idiom
to treat someone in a way that shows a lack of respect for the friendship
I can't believe you lied to me. I feel as if you've betrayed our friendship.