To deliver into the hands of an enemy by treachery or fraud, in violation of trust; to give up treacherously or faithlessly; as, an officer betrayed the city.

To prove faithless or treacherous to, as to a trust or one who trusts; to be false to; to deceive; as, to betray a person or a cause.

deliver to an enemy by treachery; "Judas sold Jesus"; "The spy betrayed his country"

To violate the confidence of, by disclosing a secret, or that which one is bound in honor not to make known.

To disclose or discover, as something which prudence would conceal; to reveal unintentionally.

To show or to indicate; -- said of what is not obvious at first, or would otherwise be concealed.

To mislead; to expose to inconvenience not foreseen to lead into error or sin.

To lead astray, as a maiden; to seduce (as under promise of marriage) and then abandon.

disappoint, prove undependable to; abandon, forsake; "His sense of smell failed him this time"; "His strength finally failed him"; "His children failed him in the crisis"