In a nutshell
意味：きわめて簡潔に言えば、要するに
I will put it in a nutshell.
かいつまんでお話ししましょう.
This, in a nutshell, is the situation.
要するに［簡単に言えば］事情はこうなのです.
I would like to say a lot more, but to put it in a nutshell, your plan was a complete failure.
まだいろいろ言いたいことはあるが, つまりは君の計画は大失敗だったということだよ.
Idiomatic usage
The expression "in a nutshell" (of a story, proof, etc.) means "in essence", metaphorically alluding to the fact that the essence of the nut - its edible part - is contained inside its shell. The expression further gave rise to the journalistic term nut graph, short for nutshell paragraph.
In Hamlet (Act 2, Scene 2) the title character exclaims: "O God, I could be bounded in a nutshell, and count myself a King of infinite space". Pliny the Elder mentioned in the encyclopedic Naturalis historia a report by Cicero saying that a handwritten version of the Iliad by Homer would have fit in a nut[shell]: "in nuce inclusam Iliadem Homeri carmen in membrana scriptum tradit Cicero".[3]