馬鹿 (baka) means “foolish,” “stupid,” or “fool.” It can be teasing between close friends or deeply insulting, depending on tone and relationship. 馬鹿にする means to mock or make light of someone. アホ is a related word whose feel varies by speaker and region.
also baka / バカ / ばか / 馬鹿な / 馬鹿にする
idiot; fool · absurd · absurdly — as an intensifier
Sentences
馬鹿だなあ · fond, between friends
plain。
Hover, tap, or tab through the words.
馬鹿
ばか ［1］
idiot; fool
noun · between friends this is affectionate; flat and cold it is not
Ask Rikai
だ
だ
is
plain copula · です in polite speech
Ask Rikai
なあ
なあ
really, you are
sentence-final particle · drawn out, it turns judgement into fondness
Ask Rikai
You idiot.
馬鹿にする · the real insult
casual。
Hover, tap, or tab through the words.
馬鹿
ばか ［1］
a fool
noun · the object of the treating, not a name being called
Ask Rikai
に
に
as — the treatment
particle · 〜にする, treat as; here, treat someone as a fool
Ask Rikai
しないで
しないで
don't do
negative て-form of する · a request not to, softer than しないでください
Ask Rikai
よ
よ
I mean it
sentence-final particle · pushes the request at the listener
Ask Rikai
Don't patronise me.
そんな馬鹿な · absurd, not stupid
plain。
Hover, tap, or tab through the words.
そんな
そんな
that sort of
determiner · points at what was just said
Ask Rikai
馬鹿
ばか ［1］
absurd
noun · here the quality, not a person — nobody is being called anything
Ask Rikai
な
な
linking な
na-adjective ending · and the noun it should modify is left unsaid
Ask Rikai
That can't be right.
関西ではアホ · the regional flip
plain。
Hover, tap, or tab through the words.
関西
かんさい ［1］
Kansai
proper noun · the Osaka–Kyoto region; 関東 is the Tokyo one
Ask Rikai
で
で
in; at — where it happens
particle · where the action happens, or the manner it happens in
Ask Rikai
は
は
as for — the topic
particle · written は, read わ
Ask Rikai
アホ
アホ
idiot — Kansai
noun · in Osaka this is the light, affectionate one and 馬鹿 is the harsh one
Ask Rikai
と
と
that — quoting
quotative particle · marks the word being reported
Ask Rikai
言う
いう ［0］
say
godan verb · a general statement about what people say
Ask Rikai
In Kansai they say aho instead.
馬鹿正直 · 馬鹿 as an intensifier
plain。
Hover, tap, or tab through the words.
馬鹿
ばか ［1］
absurdly — intensifier
prefix use · in front of a quality it exaggerates the degree, insulting nobody
Ask Rikai
正直
しょうじき ［3,4］
honest
na-adjective · honesty as a trait; 正 correct ＋ 直 straight
Ask Rikai
な
な
linking な
na-adjective ending · what 正直 needs before the noun it modifies
Ask Rikai
人
ひと ［0］
person
noun · 馬鹿正直な人 — the whole compound modifies it
Ask Rikai
だ
だ
is
plain copula · a flat description
Ask Rikai
He's honest to a fault.
Forms
Person ＋ は＋馬鹿だ
The flat statement, and the harshest shape. Said about someone present it is a fight; said about yourself it is self-deprecation.
馬鹿な＋Noun
馬鹿 is a noun, so it modifies with な: 馬鹿な話, 馬鹿なこと. Aimed at the idea rather than the person, which is much easier to survive.
Person ＋ を＋馬鹿にする
To belittle. Note it is not calling someone stupid — it is treating them as though they were, which is the accusation people actually mind.
馬鹿＋Adjective
馬鹿でかい absurdly big, 馬鹿高い absurdly expensive, 馬鹿正直 honest to a fault. Colloquial, and it carries no insult to anyone.
Meaning
The range is enormous. Between friends 馬鹿だなあ is close to you idiot said fondly, and it is one of the commonest things anyone says. Aimed at a stranger, or delivered flat at someone you are angry with, it is a real insult with nothing playful in it. Tone and relationship carry almost all of the meaning.
Usage varies by region and person. 馬鹿 is especially common around Tokyo, while アホ is common around Osaka. Some Kansai speakers hear 馬鹿 as sharper, and some Kanto speakers feel that way about アホ. Tone and relationship still matter more than a map.
馬鹿にする is the phrase that wounds. It does not mean calling someone stupid; it means treating them as beneath you. 馬鹿にしないで — don't patronise me — is a far more serious complaint than being called 馬鹿, and it is what arguments in Japanese actually turn on.
In front of an adjective it stops being an insult at all. 馬鹿でかい is absurdly huge, 馬鹿高い ridiculously expensive, 馬鹿正直 honest to a fault. The word is doing the job English gives to stupidly in stupidly expensive — an intensifier aimed at the degree, not at a person.
Inside the word
馬 horse and 鹿 deer have nothing to do with foolishness. They are 当て字 — characters picked for their sound — and the word itself is usually traced to Sanskrit by way of Buddhist vocabulary. The characters came afterwards.
A Chinese court tale has a minister present a deer as a horse to see who dares contradict him — 鹿を指して馬と為す. It is a good story and it is repeated everywhere as the origin of 馬鹿, but the connection is disputed, and the characters were probably fitted to an existing word.
Kanjium gives 馬鹿 ［1］ — the fall is right after ば. In practice you will see it as バカ far more often than 馬鹿: katakana is the default for shouting, and the kanji look oddly formal for what the word does.
Watch out
The affectionate reading depends entirely on the relationship. Between friends it is nothing; aimed at someone you do not know, or said flat in anger, it is a straightforward insult and will be taken as one.
In Kansai アホ is the everyday teasing word and 馬鹿 is the one that means it. In Tokyo the weights are reversed. The safest move as a learner is to use neither about people and recognise both.
They are different accusations. 馬鹿だ calls someone stupid; 馬鹿にする says you are looking down on them. The second is the one that ends friendships.
In front of an adjective the word is only an intensifier — 馬鹿高い is ridiculously expensive and nobody is being called anything. The same goes for 馬鹿正直 and 馬鹿でかい.
Also asked
Idiot, fool — and, applied to a thing rather than a person, absurd. It is a noun, so it modifies with な: 馬鹿な話, a stupid story. How hard it lands depends almost entirely on tone and on who is saying it to whom.
It can be either. Between friends it is affectionate and extremely common; said flat to a stranger or in anger it is a real insult. English idiot has roughly the same spread, and the same dependence on delivery.
馬鹿 is especially common around Tokyo and アホ around Osaka. Some speakers hear the less familiar regional word as harsher, but tone and relationship matter.
To belittle someone — to treat them as a fool rather than to call them one. 馬鹿にしないで is don't patronise me, and it is a heavier complaint than being called 馬鹿 outright.
They are 当て字 — characters chosen for sound rather than meaning. The word is generally traced to Buddhist vocabulary from Sanskrit, and the popular story about calling a deer a horse at a Chinese court is a later fit, not a settled etymology.
Ridiculously expensive. In front of an adjective 馬鹿 is a colloquial intensifier and carries no insult — the same use gives 馬鹿でかい absurdly big and 馬鹿正直 honest to a fault.
References
Kotobank: 馬鹿 — Defines foolishness and insult senses; identifies 馬鹿 as ateji.
Kagawa University paper on アホ and バカ usage — Discusses regional distribution and differences in how speakers receive the two terms.
Nearby
That's the whole list. rikAI is an iPhone app and it isn't out yet.
See what rikAI does · How it works · All grammar points · Language concepts
