Translation guide
The English word 'idiotic' describes something extremely foolish, stupid, or senseless. In Japanese, the most common and direct equivalent is ばかげた (bakageta), but there are several other expressions that convey similar meanings with different nuances, registers, and intensities. This guide organizes the most useful Japanese options by the specific shade of meaning you want to express.
To describe an action, idea, or situation as extremely stupid, senseless, or lacking intelligence.
The most common and versatile adjective meaning 'idiotic' or 'absurd'. It can modify nouns directly. Suitable for both spoken and written Japanese.
それはばかげた考えだ。
That's an idiotic idea.
ばかげた質問をするな。
Don't ask idiotic questions.
Means 'foolish' or 'stupid'. Slightly more formal and literary than ばかげた. Often used in serious contexts or written language.
愚かな過ちを犯した。
I made an idiotic mistake.
Means 'stupid', 'dumb', or 'idiotic' with a nuance of being slow-witted or lacking common sense. Often used for people or their actions. Casual.
間抜けな顔をしている。
He has an idiotic look on his face.
Emphasizes absurdity or ridiculousness. Often used when something is so stupid it's laughable or not worth taking seriously.
そんな話は馬鹿馬鹿しい。
That story is idiotic.
Kansai dialect equivalent of 馬鹿馬鹿しい. Very casual and regional. Use only in informal settings or with Kansai speakers.
阿呆らしくてやってられへん。
It's so idiotic I can't deal with it.
To describe something that makes no sense, is illogical, or is ridiculously impractical.
Means 'absurd', 'preposterous', or 'fantastic'. Often used for stories, plans, or ideas that are wildly unrealistic. Formal/literary.
彼の提案は荒唐無稽だ。
His proposal is idiotic.
Means 'nonsensical', 'random', or 'irresponsible'. Implies lack of logic or basis. Common in speech.
でたらめな言い訳をするな。
Don't give idiotic excuses.
Means 'incoherent' or 'disjointed'. Used for speech or writing that is so illogical it's idiotic. Formal.
彼の説明は支離滅裂だった。
His explanation was idiotic.
To call someone an idiot or a stupid person.
The most common word for 'idiot' or 'fool'. Can be used insultingly or affectionately depending on context. Very versatile.
お前は本当に馬鹿だな。
You're really idiotic.
Kansai dialect for 'idiot'. Similar to 馬鹿 but regionally marked. Often used in comedy or casual Kansai speech.
Means 'blockhead' or 'dunce'. Emphasizes slowness or lack of sharpness. Can be insulting.
この間抜けが！
You idiot!
Formal/literary term for 'fool'. Often used in serious rebukes or dramatic contexts.
While 馬鹿 (baka) is common, directly calling someone 'idiotic' in Japanese can be more offensive than in English depending on tone and relationship. Use with caution. In many situations, it's safer to describe the action or idea as foolish rather than the person.
その行動は愚かだった。
That action was idiotic.
ばかげた is more colloquial and directly corresponds to 'idiotic' in everyday speech. 愚かな is more formal and often used in writing or serious criticism. Choose based on context.
ばかげた間違い (casual)
idiotic mistake (casual)
愚かな判断 (formal)
idiotic judgment (formal)
That guy is idiotic.
彼は愚か者だ。
He is an idiotic person.