n. In anatomy, the external organs of generation of the female; especially, the orifice of these parts, the external termination of the vagina—of an elliptical contour in the human female.n. In entomology, the orifice of the oviduct.n. In conchology, the oval or vulviform conformation presented by certain bivalve shells when the right and left valves are in apposition. See Veneridæ