Grundel

1. (n.) The area of skin between the anus and the genitalia in either sex (see also 'taint) 2. (v.) A complex variation of "mooning" in which one applies the flesh of one's bare buttocks (usually the hairier buttocks of the male) directly to the face of the victim, especially when the victim is seated on the floor and distracted. To apply one's buttocks to the back of the NECK of someone seated on the floor is known as a "reverse Grundel."