To slip one's knuckle into the crack of an unsuspecting victim. Similar to a credit card but using the knuckle.
by akellz April 17, 2012
Jeremy's motto is "your not gay if a girl is doing it to you. Guess you can say he's a knuckle butt.
by Ballard757 January 30, 2011
(noun) The popping sound made by an explosive fart. A crisp and short passage of gas from ones butt.
by Jay Hoe September 04, 2009
1.)The smelly brown knuckle of the finger or thumb inserted in someones butt. 2.)The person inserting said finger or thumb 3.) The act of inserting said finger or thumb in one's butt, possibly due to boredom or lack of interest. 4.)Someone who complains alot but does nothing and/or offers no suggestions about how to remedy the problem he/she is complaining about.
Dave is such a butt-knuckle that rather than do something useful he'll just sit there with his thumb up his butt complaining about everything. Hey can you help me with this right after you go wash the stink off of your butt-knuckle. Don't go butt-knuckle on us now we may still need your help before it's all over.
by Bradley Brandt November 01, 2005
When a male wears his pants/shorts extra tight and his balls are showing. The opposite of Camel Toe.
by Skinnywalker January 13, 2005
The consensual act of having aggressive anal sex with someone who has horrific hemorrhoids in order to break them down
Angie knew when she had got hemorrhoids again it was time for Peter to start bustin' butt knuckles to get some relief
by von groovy April 11, 2019