Top definition
The muscle developed in the forearm from jerking off too much. Often exaggerated amongst friends to make one appear to jerk off more than they might.
Mike: Dude, you been going to the gym yet?
Nate: I started going a week ago.
Shannon: Don't listen to him, we broke up a week ago and that's just his jerk muscle gone crazy.
by Skrait Buttah July 29, 2006
Mug icon

The Urban Dictionary Mug

One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.

Buy the mug