A fork of Rural Dictionary
knees with fat on them that makes them look like melted butter; weird ass knees; fat knees
hey look at that girl's butter knee
The build-up of sweat and dead skin congealed into a buttery substance. Generally found within deep fat crevices i.e. - knee or elbow area.
It's so hot out, I could slather a whole loaf of bread with my knee-butter.
I need to jump in the shower right quick before the knee-butter begins to solidify.