n. The region of the body between the thighs, extending from the anus to the fourchette in the female, or to the scrotum in the male.n. The region included by the outlet of the pelvis, extending from the apex of the subpubic arch in front to the tip of the coccyx behind, and bounded laterally by the conjoined pubic and ischiatic rami, the tuberosities of the ischia, and the great sacrosciatic ligaments.