1
general::
Concisely, in a few words, as in Here's our proposal? in a nutshell, we want to sell the business to you. This hyperbolic expression alludes to the Roman writer Pliny's description of Homer's Iliad being copied in so tiny a hand that it could fit in a nutshell. For a time it referred to anything compressed, but from the 1500s on it referred mainly to written or spoken words.
American Heritage Idioms
2
general::
Phrase(s): in a nutshell
Fig. [of news or information] in a (figurative) capsule; in summary. • This cable channel provides the latest news in a nutshell. • In a nutshell, what happened at work today?
McGrawhill's American Idioms And Phrasal Verbs