Translation guide
The English word "stupid" covers a wide range of meanings from low intelligence to foolish actions, annoying things, and even informal intensifiers. Japanese has many words for these nuances, but direct translations can sound harsh or unnatural. This guide organizes the most useful Japanese expressions by the intended English meaning.
Describing someone who is not smart, slow-witted, or unintelligent.
The most common and versatile word for 'stupid' or 'fool'. Can be used as a noun or adjective. Mildly insulting; can be playful among close friends.
彼は馬鹿だ。
He is stupid.
馬鹿なことを言うな。
Don't say stupid things.
Kansai dialect equivalent of 馬鹿, but widely understood. Often sounds softer or more humorous than 馬鹿 in standard Japanese.
あいつはアホやな。
That guy is stupid, isn't he? (Kansai dialect)
More formal and literary word for 'foolish' or 'stupid'. Often used in writing or serious contexts.
それは愚かな判断だ。
That is a foolish decision.
Means 'stupid' in the sense of being slow, dim-witted, or a blockhead. Often implies a lack of common sense.
彼は間抜けな顔をしている。
He has a stupid look on his face.
Describing an action, idea, or decision that is unwise, senseless, or shows poor judgment.
Adjective meaning 'absurd', 'ridiculous', or 'stupid'. Used for actions or ideas that are clearly foolish.
それは馬鹿げた考えだ。
That's a stupid idea.
馬鹿げた質問をするな。
Don't ask stupid questions.
Common phrase meaning 'to do something stupid'. Versatile and natural in conversation.
また馬鹿なことをした。
I did something stupid again.
As above, but used for actions/decisions. Formal tone.
愚かな行為だ。
It's a stupid act.
Means 'trivial', 'worthless', or 'stupid' in the sense of being pointless or silly. Often used for jokes, ideas, or things that waste time.
Expressing frustration that something is irritating, troublesome, or not working properly. Often used as 'This stupid thing!'
Can be used attributively to mean 'damn' or 'stupid' for inanimate objects causing frustration.
この馬鹿な機械がまた壊れた。
This stupid machine broke again.
Means 'unpleasant' or 'disagreeable'. A softer way to express annoyance without strong insult.
嫌な天気だな。
Stupid weather, huh.
Slang for 'pissed off' or 'annoying'. Used when something makes you angry or frustrated.
Using 'stupid' informally to mean 'very' or 'extremely', e.g., 'stupid hot', 'stupid expensive'.
Common colloquial intensifier meaning 'ridiculously' or 'insanely'. Works for both positive and negative adjectives.
今日はめちゃくちゃ暑い。
It's stupid hot today.
その車、めちゃくちゃ高いよ。
That car is stupid expensive.
Standard intensifier meaning 'very' or 'really'. Less emphatic than めちゃくちゃ but more neutral.
すごく寒いね。
It's stupid cold, isn't it?
Prefix meaning 'absurdly' or 'stupidly'. Can be used with some adjectives, but less common and can sound rough.
Not as flexible as English 'stupid + adjective'. Often limited to set phrases like バカ高い (stupid expensive) or バカでかい (stupid huge).
バカ高い家賃
stupidly high rent
Being so in love that you act foolishly or can't think straight. E.g., 'I'm stupid in love.'
Proverb meaning 'love is blind'. Captures the idea of being stupid because of love.
恋は盲目って言うでしょ。
They say love is blind, you know.
To be infatuated or carried away with love, often acting foolishly.
To be giddy or light-headed with love, making one act silly.
彼女は恋に浮かれて何も手につかない。
She's so stupid in love she can't focus on anything.
Pretending not to know or understand something.
To play dumb, feign ignorance. Very common in conversation.
とぼけないでよ。
Don't play stupid.
彼は知っているくせにとぼけた。
He played stupid even though he knew.
To feign innocence, especially when accused of something. Stronger nuance of denying knowledge.
To pretend not to know or notice; to ignore deliberately.
彼女は私を見ても知らんぷりをした。
She played stupid and ignored me even though she saw me.
Calling someone 馬鹿 directly to their face is a strong insult and can cause serious offense. Use with caution, and only among very close friends in jest. In formal or polite situations, avoid any direct 'stupid' labels.
お前は馬鹿か？
Are you stupid? (very rude)
In standard Japanese, 馬鹿 is the default word for 'stupid'. アホ is strongly associated with the Kansai region (Osaka, Kyoto, etc.) and can sound softer or more humorous to standard Japanese speakers. However, in Kansai, アホ is the normal word and 馬鹿 can sound harsher. Be aware of regional differences.
Instead of directly calling someone stupid, Japanese often uses phrases like ちょっと考えが足りない (a bit lacking in thought) or あまり賢くない (not very smart). This is more polite and indirect.
それは馬鹿なミスだった。
That was a stupid mistake.
彼を信じた自分が馬鹿みたいだ。
I feel stupid for believing him.
この馬鹿な電話、動かない！
This stupid phone won't work!
くだらないことで悩むな。
Don't worry about stupid things.
このパソコン、むかつく！
This stupid computer is pissing me off!
彼は彼女にのぼせ上がっている。
He's stupid in love with her.
彼は白を切ったが、証拠がある。
He played stupid, but we have evidence.