Translation guide
The English word "nut" covers food nuts, mechanical nuts, and slang uses. This guide focuses on the most common meanings for learners: the food item, the hardware piece, and a few idiomatic expressions.
Referring to a hard-shelled dry fruit or seed, often eaten as a snack or used in cooking.
The most common and general word for nuts as a food category, especially mixed nuts or snack nuts. A loanword from English.
おつまみにナッツを食べた。
I ate some nuts as a snack.
Literally 'tree fruit/seed'. Refers to nuts and berries from trees, often in a natural or poetic context. Can include acorns, chestnuts, etc.
リスが木の実を集めている。
The squirrel is gathering nuts.
Botanical term for a true nut (hard-shelled fruit). Rare in everyday conversation; used in scientific contexts.
ドングリは堅果の一種です。
Acorns are a type of nut.
A small metal block with a threaded hole, used with a bolt.
Standard term for a mechanical nut. Loanword from English.
ボルトにナットを締めてください。
Please tighten the nut onto the bolt.
Can mean screw, bolt, or nut depending on context. Often used in compounds. Less precise than ナット.
螺子が緩んでいた。
The nut/screw was loose.
A person who is eccentric, crazy, or obsessed with something.
Means 'eccentric person' or 'weirdo'. Closest to calling someone a 'nut' in a light-hearted way.
彼はちょっと変人だけど面白い。
He's a bit of a nut, but interesting.
Means 'lunatic' or 'madman'. Stronger and more negative than 変人. Use with caution.
Can be offensive; not a casual 'nut'.
Means 'enthusiast' or 'fanatic'. Used for someone obsessed with a hobby (e.g., car nut).
彼は車のマニアだ。
He's a car nut.
Slang for a person's head, often in phrases like 'off one's nut' or 'use your nut'.
Standard word for 'head'. Can be used in similar contexts, but the slang nuance is lost.
自分の頭を使え。
Use your nut (head).
Means 'crazy' or 'not right in the head'. Equivalent to 'off one's nut'.
あいつは頭がおかしい。
He's off his nut.
A hard nut to crack: a difficult problem or person to understand.
Means 'tough problem'. Natural equivalent for 'a hard nut to crack'.
これは手強い問題だ。
This is a hard nut to crack.
Means 'difficult thing/person'. Can be used for a person who is hard to deal with.
彼はなかなかの難物だ。
He's a tough nut to crack.
Slang for testicles. Often used in the plural 'nuts'.
Vulgar slang for testicles. Literally 'gold balls'. Very informal.
サッカーボールが金玉に当たった。
The soccer ball hit him in the nuts.
Medical/anatomical term for testicles. Not slang.
While 木の実 is correct, using it for snack nuts sounds poetic or old-fashioned. Stick to ナッツ for modern snacks.
ピーナッツはナッツの一種です。
Peanuts are a type of nut.
変人 is a mild 'weirdo', while 狂人 implies serious mental instability. Use 変人 for a harmless eccentric, and avoid 狂人 unless you mean 'lunatic'.
彼は変人扱いされている。
He's treated like a nut.
Get away from that nut.
睾丸の検査を受けた。
I had a testicular exam.