Pledge

v. t.
  1. To deposit, as a chattel, in pledge or pawn; to leave in possession of another as security; as, to pledge one's watch.
  2. To give or pass as a security; to guarantee; to engage; to plight; as, to pledge one's word and honor.
  3. To secure performance of, as by a pledge.
  4. To bind or engage by promise or declaration; to engage solemnly; as, to pledge one's self.
  5. To invite another to drink, by drinking of the cup first, and then handing it to him, as a pledge of good will; hence, to drink the health of; to toast.