look up any word, like bukkake:
Weasel butter is the build up of piss that ends up on urinals, toilets, and bathroom floors. As the pee dehydrates it takes the appearence of butter.and since you leak your weasel, it's called weasel butter.
Damn there is so much weasel butter on the floor you could cook eggs on it.
by original gasbag September 27, 2013