Phlegm. The thicker, the more yellow, the more flavorful, the better...I wouldn’t recommend spreading it on your toast though.
The worst part of being sick is hacking up a mouthful of lung butter when you have no place to spit.
by LeftCoastOriginal November 20, 2018
The viscous, yellow-green fluid coughed up after playing a reeded instrument for a prolonged period of time. Such as a clarinet or the bagpipes
Man 1: i played my pipes for three hours yesterday and had to cough up about four pounds of lung butter.
Man 2: dude that's gross why don't you just quit the band?
Man 1: because highlanders is life.
Man 2: dude that's gross why don't you just quit the band?
Man 1: because highlanders is life.
by Therealrothman November 25, 2016