Nŭt’shĕll, n.

noun

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

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

To be or lie in a nutshell, to admit of very brief or simple determination or statement. “The remedy lay in a nutshell.” Macaulay.