The action of betraying; betrayal of the trust undertaken by or reposed in any one; breach of faith, treacherous action, treachery.

With a and plural. An instance of this, an act of perfidy or treason.

Betrayal, treachery.

The action of betray, v. in various senses; betrayal.

= betraying, n.

Treason, treachery; betrayal; an instance of this.

Betrayal.

The action of handing over something or (now rarely) someone to another; delivery, transfer. In early use often in negative sense: †the action or an…

Treachery, treason, perfidy; an instance of this.

Dishonest, unscrupulous, or criminal conduct.

= Betrayal.

treacherous dealing (obsolete).

= betrayal, n.

A treacherous giving up to an enemy.

= treason, n.

Originally: the practice of winning or trying to win a match after making an illicit deal to lose (cf. double-cross, n. 2a). In later use more…

Treason.

The action of betraying, informing, ‘telling on’ someone. Frequently as dobbing in.