Small lint ball like object found either in the pubic region of a woman or stuck to the clammy, sticky lips of her vagina.
Your mother must have had a hundred gundersuns stuck to her clam hole.
by Ada Gundersun August 30, 2003
(noun)unidentified crusty object stuck on the end of a women's pubic hair
Hey, have you been eating cookies naked again or is that a gundersun?
by sister luke August 31, 2003