a stain found in your undies.... like after you have a viscocity fart
i have a fart stain!
by Ciske November 02, 2003
visible markings left typically in the undergarments of a personage having passed a flatus can be a spry alluding to a person as useful as the preceding definition
As Johnny disrobed his boxers sported a mustard brown fartstain.
by schultheis, sj July 04, 2006