—n. 1. a solemn promise or agreement to do or refrain from doing something: a pledge of aid; a pledge not to wage war. 2. something delivered as security for the payment of a debt or fulfillment of a promise, and subject to forfeiture on failure to pay or fulfill the promise.
3. the state of being given or held as security: to put a thing in pledge. 4. Law. a. the act of delivering goods, property, etc., to another for security.
b. the resulting legal relationship.
5. something given or regarded as a security.
6. a person accepted for membership in a club, fraternity, or sorority, but not yet formally approved.
7. an assurance of support or goodwill conveyed by drinking a person's health; a toast.
8. Obs. a. a hostage.
b. a person who becomes bail or surety for another.
9. take the pledge, to make a solemn, formal vow to abstain from intoxicating drink.
—v.t. 1. to bind by or as if by a pledge: to pledge hearers to secrecy. 2. to promise solemnly: to pledge one's support. 3. to give or deposit as a pledge; pawn.
4. to stake, as one's honor.
5. to secure by a pledge; give a pledge for.
6. to accept as a pledge for club, fraternity, or sorority membership.
7. to drink a health or toast to.
—v.i. 1. to make or give a pledge: to pledge for someone. 2. to drink a pledge; toast someone's health, success, etc.