iliac (il-i-ak) adj. relating to the ilium. i. arteries the arteries that supply most of the blood to the lower limbs and pelvic region. i. fossa a concave depression on the inside of the pelvis. The right iliac fossa provides space for the vermiform appendix. i. veins the veins draining most of the blood from the lower limbs and pelvic region.

il·i·ac / ˈilēˌak/ • adj. of or relating to the ilium or the nearby regions of the lower body: the iliac artery.