To put or bring together; bring into conjunction, or into association or harmony; unite; combine; associate: as, to join two planks by tenons; to join forces in an undertaking.To unite, as one thing to or with another; bring into conjunction or association; cause to be united or connected in any way: followed by to or with.To unite or form a junction with; become connected with or a part of; come into association or union with: as, to join a church, party, or society; the Missouri river joins the Mississippi; to join one in an enterprise.To unite or take part in, in a friendly or hostile manner; engage in with another or others: as, he joined issue with his opponent; the forces joined battle.To adjoin; be adjacent or contiguous to: as, his land joins mine.To enjoin; command.To be contiguous or close; lie or come together; form a junction.To unite or become associated; confederate; league.To meet in hostile encounter; join battle.n. The place where two things are joined; the line or surface of juncture; a joint; also, the mode of joining.To draw, as the sect of which A and B are the end points.n. In geometry, the straight determined by two points.n. An abbreviation of joinery.