The term "crust" can refer to several different meanings depending on its context.
In geology, crust refers to the outermost layer of a planet or moon that is composed of solid rock and may include soil or regolith. It is thinner than the mantle below it but thicker than the outer core above it.
In baking, "crust" typically refers to the hard, dry exterior covering of bread, cakes, pies, and other baked goods made from flour. The texture and taste of crust can vary depending on how it is prepared or cooked.
Additionally, in astronomy, a crust is a type of meteoroid that has a thin layer of rock surrounding a core of ice. These types of meteors are called "stony" because they have a harder outer surface compared to the more common "dirty snowballs."