The white creamy stuff left on your chin strap after a long day of laxing in hot weather. It is made of old sweat and is very uncomfortable.
" Holy shit, I just put on my helmet and my chin strap is covered with chin butter from a week ago!"
by lax de PW March 23, 2009
1. Cum spread on one's face like a peanut butter sandwich.
This fine girl at the party asked Chris Charles to give her some chin butter, but he didn't know how to give it to her.
by Jared Deutsch February 20, 2005