An agreement between two or more parties, especially one that is written and enforceable by law. See Synonyms at bargain. The writing or document containing such an agreement. The branch of law dealing with formal agreements between parties. Marriage as a formal agreement; betrothal. Games The last and highest bid of a suit in one hand in bridge. Games The number of tricks thus bid. Games Contract bridge. A paid assignment to murder someone: put out a contract on the mobster's life. To enter into by contract; establish or settle by formal agreement: contract a marriage. To acquire or incur: contract obligations; contract a serious illness. To reduce in size by drawing together; shrink. To pull together; wrinkle. Grammar To shorten (a word or words) by omitting or combining some of the letters or sounds, as do not to don't. To enter into or make an agreement: contract for garbage collection. To become reduced in size by or as if by being drawn together: The pupils of the patient's eyes contracted. contract out To engage a person outside an organization by contract to undertake or produce.