Vagina: The muscular canal extending from the cervix to the outside of the body. It is usually six to seven inches in length, and its walls are lined with mucus membrane. It includes two vaultlike structures, the anterior (front) vaginal fornix and the posterior (rear) vaginal fornix. The cervix protrudes slightly into the vagina, and it is through a tiny hole in the cervix (the os) that sperm make their way toward the internal reproductive organs. The vagina also includes numerous tiny glands that make vaginal secretions.

The word "vagina" is a Latin word meaning "a sheath or scabbard", a scabbard into which one might slide and sheath a sword. The "sword" in the case of the anatomic vagina was the penis. Love and war, it would seem, have been connected in the minds of people for millennia.