look up any word, like smh:
 
1.
Shit on your hand or knuckle when wiping one's ass.
While wiping I got a case of the brown knuckle.

My roommate had brown knuckle on his finger.
by john January 19, 2004
 
2.
When some one wipes their ass and their thumb knuckle hits their asshole before the toilet paper does, causing them to have shit on their knuckle.
Tom had to use extra soap to get off the brown knuckle.
by Iambetterthanu February 14, 2008
 
3.
The failed act of fisting, due to lower intestinal blockage.
Jimmy want to fist his girl, but she was to full to engage, leaving Jimmy with a nasty case of the brown knuckles.
by Jimmy May 13, 2003
 
4.
To fist another's ass.
Heather bent over amber, made a fist and gave her a brown knuckle.
by Brown Fist October 06, 2003