Wordnet 3.0
NOUN (2)
1.
a freely moving joint in which a sphere on the head of one bone fits into a rounded cavity in the other bone;
[syn: ball-and-socket joint, spheroid joint, cotyloid joint, enarthrodial joint, enarthrosis, articulatio spheroidea]
2. a joint that can rotate within a socket;
WordNet (r) 3.0 (2006):
ball-and-socket joint
n 1: a freely moving joint in which a sphere on the head of one
bone fits into a rounded cavity in the other bone [syn:
ball-and-socket joint, spheroid joint, cotyloid
joint, enarthrodial joint, enarthrosis, articulatio
spheroidea]
2: a joint that can rotate within a socket