Tainted knuckles occur when you reach between your legs to wipe your ass after a shit and your knuckles touch the vile soup in the toilet bowl or,heaven forbid,the turd itself.
by wolfbait51 May 29, 2011
Someone that shoves all their fingers into a females vagina, so that their knuckles are touching the taint...
by The Judge of the Northeast April 26, 2015