The hard external coat or covering of anything; the hard exterior surface or outer shell; an incrustation; as, a crust of snow.
- The hard outer portion or surface area of bread.
- A piece of bread consisting mostly of the hard outer portion.
- A piece of bread that has become hard and dry.
- A pastry shell, as of a pie or tart.
- A hard crisp covering or surface: snow with a firm crust.
- A hard deposit formed on the interior of a wine bottle as the wine matures.
- Geology The exterior portion of the earth that lies above the Mohorovičić discontinuity.
- Geology The outermost solid layer of a planet or moon.
- The hard outer covering or integument of certain plants and animals, such as lichens and crustaceans.
- Pathology An outer layer or coating formed by the drying of a bodily exudate such as pus or blood; a scab.
- Informal Insolence; audacity; gall.
- To cover with a crust.
- To form into a crust.
- To become covered with a crust.
- To harden into a crust.