The unfortunate event when the toilet paper you are wiping with skims and slips off your ass, thus causing your knuckles to graze your half-wiped ass. A smell check of the offending knuckles will confirm or deny whether you need to cut off your hand.
This dollar store toilet paper offered me no ass traction; a knuckle graze occured, and now my knuckles look like shitty brown mountains.
by SavageNation June 5, 2009
Get the Knuckle grazemug.