The vagina (from Latin vāgīna, literally "sheath" or "scabbard") is a fibromuscular tubular tract which is a sex organ and has two main functions; sexual intercourse and childbirth. In humans, this passage leads from the opening of the vulva to the uterus (womb), but the vaginal tract ends at the cervix. Unlike men, who have only one genital orifice, women have two, the urethra and the vagina. The vaginal opening is much larger than the urethral opening, and both openings are protected by the labia. The inner mould of the vagina has a foldy texture which can create friction for the penis during intercourse. During arousal, the vagina gets moist to facilitate the entrance of the penis.
The Latinate plural "vaginae" is rarely used in English. In casual conversation, the word vagina is often used to refer to the vulva or to the female genitals in general. The traditional dictionary definition refers exclusively to the specific internal structure.
Read more about Vagina: Location and Structure, Clinical Relevance, In Non-human Animals