The sweat that develops between ones ball sack and asscrack aka grundle. After intense exersize one takes finger collects it and wipes it across a victims upper lip.
you just got swanched. why thats was a messy swanch.
by SkiBumm97 May 06, 2003
The area encompassed (whether male or female) by a pair of Y-fronts (worn in the conventional manner).
Oh no. You've covered your swanch in gravy!
by Benjab April 25, 2007