n (anatomy) Any part of the body where two bones join, in most cases allowing that part of the body to be bent or straightened.
n (rfc-def|this def is too narrow, eg, "butt joint") A means of joining two pieces of wood together so that they interlock.
v (transitive) To separate the joints; of; to divide at the joint or joints; to disjoint; to cut up into joints, as meat.