queef

Vaginal flatulence is an emission or expulsion of air from the vagina. It may occur during or after sexual intercourse or during other sexual acts, stretching or exercise. The sound is somewhat comparable to flatulence from the anus but does not involve waste gases and thus often has no specific odor associated. Slang terms for vaginal flatulence include vart, queef[1][2] and fanny fart (mostly British).[3][4]

http://en.wikipedia.org/wiki/Vaginal_flatulence