Nutshell

Part of speech: noun (n.)

1. The shell or hard external covering in which the kernel of a nut is inclosed.

2. Hence, a thing of little compass, or of little value.

3. A shell of the genus Nucula. To be, or lie, in a nutshell, to be within a small compass; to admit of very brief or simple determination or statement. "The remedy lay in a nutshell." Macaulay.