the outer layer of the Earth
"The crust is the thin, solid outer shell that forms the surface of the Earth."
a hard outer layer that covers something
"The baker pulled the fresh loaf from the oven, revealing a golden crust on top."
the trait of being rude and impertinent; inclined to take liberties
"His crust attitude made it impossible for anyone to have a civil conversation with him."
A more solid, dense or hard layer on a surface or boundary.
"The thick crust of the loaf was perfect for holding the melted cheese without breaking."
In plain English: The crust is the hard, outer layer of something like bread or an egg that forms when it bakes or cooks.
"She broke off a piece of hard crust from the top of her baguette and ate it with delight."
Usage: Use "crust" to describe the hardened outer layer of baked goods like bread or pizza, but avoid using it metaphorically for skin unless referring specifically to scabs or dried secretions. Do not confuse this noun with the verb "to crust," which means to cover something with a hard coating.
To cover with a crust.
"The baker carefully brushed milk over the dough to help it form a golden crust."
The word "crust" comes from the Latin crusta, meaning a hard outer covering. It entered English through Anglo-Norman and Old French after originally describing something that had begun to freeze or solidify on its surface.