(Noun) The result of poor quality toilet paper when moderate force is used to wipe one's butt
(Noun) A person who regularly sticks their finger in a butt for personal pleasure and/or the pleasure of others e.g. "dirt knuckler"
(Verb) The inadvertent act of penetrating the toilet paper while wiping a butt e.g. "dirt knuckled" "dirt knuckling"
I got a nasty dirt knuckle after crapping on a plane.
There he goes with his finger in his butt again. He's such a dirt knuckler.
Guess I wiped my butt a little too hard because I ended up dirt knuckling.