coxa Uppermost joint of the leg of an insect, which articulates with the thorax proximally, and with the trochanter distally. The coxa is usually a stout, truncated cone of cuticle, freely mobile with respect to the thorax; but in Lepidoptera the middle and hind coxae are fused to the thorax. Muscles that move the coxae originate in the thorax.

coxa (koks-ă) n. (pl. coxae)
1. the hip bone.

2. the hip joint. c. valga a deformity of the hip joint in which the angle between the neck and shaft of the femur is abnormally increased. c. vara a deformity of the hip joint in which the angle between the neck and shaft of the femur is abnormally decreased.

coxa The first (basal) segment, attached to the thorax, of the leg of an insect, arachnid, or of certain other arthropods. See also femur; trochanter.

coxa The uppermost joint of the leg of an insect.