Stories We Like: A Guide to the Comma
1680s, from Latin vagina "sheath, scabbard" (plural vaginae), from PIE *wag-ina- (cf. Lithuanian voziu "ro cover with a hollow thing"), from root *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 Latin word was not used in an anatomical sense in classical times. Anthropological vagina dentata is attested from 1908.
vagina va·gi·na (və-jī'nə)
n. pl. va·gi·nas or va·gi·nae (-nē)
The genital canal in the female, leading from the opening of the vulva to the cervix of the uterus.
A sheathlike anatomical structure.