Crusty (adjective)

1. Having a hard and rough surface.
2. Being covered with or having a hard coating.
3. Being irritable or ill-tempered.

Origin:

From old english cruste, meaning a hard outer layer.

Examples:

1. The bread had a crunchy crust.
2. The snow was crusty on top.
3. The old man was crusty and grouchy.
4. The wound was crusty and had to be cleaned.
5. The crusty cheese was sharp and tangy.