crust Definition

1a. The hard-baked outer surface of a loaf of bread;
1b. A piece of this; a dried-up piece of bread.
2. The pastry covering a pie, etc.
3. A crisp or brittle covering.

Thesaurus: coating, exterior, rind, shell, hull, scab, surface, film, patina.
4. The dry brittle covering which forms over a skin lesion.
5. The solid outermost layer of the Earth, consisting mainly of sedimentary rocks overlying ancient igneous rocks.
6. slang
A living or livelihood.

tr & intr
crusted, crusting
1. To cover with or form a crust.