Crust
In geology, a crust is the outer layer of a planet, part of its lithosphere. Planetary crusts are generally composed of a less dense material than that of deeper layers. On partially-molten planets, such as Earth, the lithosphere is floating on fluid interior layers.
Such floating lithospheres are often broken into tectonic plates that, because of fluidity underneath, can move (see continental drift).
In baking, a crust is the outer, hard skin of bread or the shell of a pie.
music, crust is an underground hardcore genre related to Noisecore and resembling Death Metal. Its chief original exponents were the band Doom. It derives its name from the term crusty, British slang for a member of a subculture in which people would typically wear their hair in dreadlocks, use drugs and eschew traditional lifestyle choices in employment and housing (i.e. by being unemployed and squatting).
Crust is also a Texas psychedelic band on the Trance Syndicate label.
