Vagina dentata
Latin for "toothed vagina".
Often crops up as a sexist projection onto women's bodies of men's fear of women's sexuality. Devouring mothers and all that.
Sometimes appears in fiction as an instance of fantastical biology, or a science-fictional body modification or device.
As a rape deterrent, it rather rests on the presumption that men will have access to women's bodies anyhow, and that they will go far enough for a device located in the vagina to make any difference, thereby circumscribing women's inevitable position as victims. The development of a real-life version inspired criticism that they would be useless against rape committed with the help of foreign objects, or expose victims to blood-borne contagions should their attackers' skin break.
Examples
Fantasy
- Tanith Lee's "Weasel Bride"
Science-Fiction
- Neal Stephenson's Snow Crash.