1682, from L. vagina "sheath, scabbard" (pl. vaginæ), from PIE *wag-ina- (cf. Lith. voziu "ro cover with a hollow thing"), from base *wag- "to break, split, bite." Probably the ancient notion is of a sheath made from a split piece of wood (see sheath). A modern medical word; the L. word was not used in an anatomical sense in classical times. Anthropological vagina dentata is attested from 1908.
(və-jī'nə) The tube-shaped part of the reproductive tract in female mammals that is connected to the uterus at one end and opens to the outside of the body on the other end. The fully developed fetus passes through the vagina during birth.