Ĕn'ăr-thrō'sis, n.

n. [Gr. ἐνάρθρος, jointed, from ἐν, in, and ἄρθρον, joint; Fr. enarthrose.] (Anat.) A ball-and-socket joint; that species of articulation which consists in the insertion of the round end of a bone in the cup-like cavity of another, forming a joint movable in every direction.