Crust

Hardened outer layer of a substance.

bark crusty layer

A crust refers to the hardened outer layer of a substance, typically formed through baking or cooking processes. It can also describe the thin surface layer of various materials such as bread, cakes, or geological formations like Earth's crust.

The word 'crust' comes from the Old French 'crosta', meaning 'hard, rough surface'.

Crust is like the hard shell on a fruit or the top of a pie - it's a protective or outer layer that has become hardened.

surface layer

bread crust pie crust Earth's crust

bread cake planet

natural formation plant part structural component