noun
: either of two foramina on each side leading from the pelvis to the gluteal and peroneal regions and transmitting respectively (1) the sciatic nerve, superior and inferior gluteal, pudendal, and other nerves, associated vessels, and the piriformis muscle and (2) the tendon of the internal obturator muscle and the pudendal vessels and nerve — called also (1) greater sciatic foramen (2) lesser sciatic foramen