noun

1. A hard external covering of an animal.

2. The hard calcareous covering of a bird egg.

3. One of the outer layers of skin of an onion.

   “The restaurant served caramelized onion shells.”

Synonyms: shell-like

verb

1. To remove the outer covering or shell of something.

2. To bombard, to fire projectiles at, especially with artillery.

3. To disburse or give up money, to pay. (Often used with out).