The Collaborative International Dictionary of English v.0.48:
Coxa \Cox"a\ (k?ks"?), n. [L., the hip.] (Zool.) The first joint of the leg of an insect or crustacean. [1913 Webster] CoxalgiaWordNet (r) 3.0 (2006):
coxa n 1: the ball-and-socket joint between the head of the femur and the acetabulum [syn: hip, hip joint, coxa, articulatio coxae]