The condition of having an asshole itch so intense and deep that it feels like the only way you can properly scratch it is to stick your finger up your ass all the way up to the knuckle, and scratch your asshole from the inside.
A case of knuckle ass might be the result of poor hygiene (see hanus anus) or could just be an unlucky ass itch that anyone can get from time to time.
"I took a shit this morning and I guess I didn't wipe well enough. Now I've got major knuckle-Ass"
n. A screenshot fabricated by a company to misrepresent the graphics of a game; a combination of the wordsbullshit and screenshot.
Originated from Penny Arcade, a popular gaming webcomic.
-Have you seen Madden 2006 for the Xbox 360? The graphics are gonna be awesome!
-Dude, the Madden 2006 images they showed at E3 were bullshots. It doesn't look nearly as good as they said.