LungButter

Mucus that is in your lungs or throat.

I haven't been able to breath correctly, I have been spitting LungButter all night.

by Rapture101 January 4, 2014

mudbutter

A name for the feces ring around the head of your penis after anal sex

is that mudbutter on your penis

by adamishere April 12, 2021

muckbutter

Thick scum from the bottom of your lungs.

I just knocked over my cup of muckbutter

Muckbutter does not go good on eggs, it’s better on toast.

by BlackLungJones September 9, 2023