transitive. To engage or pledge (oneself) to a person, or to do something. In later use frequently in passive: to be engaged or bound to someone.

transitive. In passive. To be bound by a promise or pledge; spec. to be engaged, to be betrothed. Frequently with to. Cf. sure, adj. 8a. Obsolete.

Now archaic. transitive. To pledge (a person, esp. a woman) in marriage to someone else; to betroth. Frequently in passive.

In the passive, now commonly used, senses 1 2 are blended.