Source : Webster's Revised Unabridged Dictionary (1913)

Coxa \Cox"a\ (k?ks"?), n. [L., the hip.] (Zo["o]l.)
   The first joint of the leg of an insect or crustacean.

Source : WordNet®

coxa
     n : the ball-and-socket joint between the head of the femur and
         the acetabulum [syn: {hip}, {hip joint}, {articulatio
         coxae}]
     [also: {coxae} (pl)]