In a nutshell means summed up in the fewest possible words. So, in a nutshell, that is it in a nutshell, put it in a nutshell.
It signals a summary and is nearly always followed by one sentence. The phrase comes from an ancient story about a copy of the Iliad written small enough to fit inside a nutshell.
1phrasein a nutshellSummed up in the fewest possible words.
“In a nutshell, the plan is to sell the house and move to the coast.”
in a nutshell is a summary.
From a Latin phrase and an ancient story of a copy of the Iliad written small enough to fit in a nutshell.
New Latin
in nuce
English, today
in a nutshell
New Latin in nuce, derived from an anecdote in Pliny the Elder, who ascribes to Cicero the claim that the whole Iliad was once written on parchment and enclosed within a nutshell (Naturalis Historia 7.21.85). Compare typologically stručný, stručně (< struk).
Etymology from Wiktionary, CC BY-SA
Practised in Idioms