Is there a Japanese equivalent term(s) to describe a brain fart/absentmindedness? I noticed the term karahenji in Jisho.

  • eow.alc.co.jp/search?q=brain+fart
    – BJCUAI
    Commented Aug 8, 2019 at 11:52
  • 2
    The options in alc are not that good though. Commented Aug 8, 2019 at 12:29
  • @DariusJahandarie True enough. I should have just suggested that they reference dictionaries other than just jisho.org. I still think 頭真っ白 is pretty close in many contexts.
    – BJCUAI
    Commented Aug 9, 2019 at 1:25

3 Answers 3


ど忘{わす}れ is a word that, like "brain fart," means roughly that you are unable to recall something in the moment, but you would normally be able to recall it easily.

It comes from 忘{わす}れる (to forget) and , a prefix that can be used for emphasis or to add a derogatory tone to something.

As noted by kimi Tanaka in a comment, it's possible that there is a difference in register between the two terms across languages, since "fart" is not a polite word, but in meaning they are very close to each other.

  • 1
    FWIW, ど忘れ is pretty casual. Of course it doesn’t have the word “fart” in it, but honestly register of the English isn’t as low as you’d expect; I feel like you can use “brain fart” even at work as long as it’s not in some really tense situation. Seems to mostly match up to me. Commented Aug 8, 2019 at 17:18
  • I also like 上の空 for this.
    – kandyman
    Commented Aug 9, 2019 at 11:17

According to Merriam Webster's dictionary, I use them for the explanation and please look up the bold part of my interpretation for the reference.

The definition of absentmindedness is the following :

Definition of absentminded

  • 1 a : lost in thought and unaware of one's surroundings or actions :

was too absentminded to notice what time it was


  • 1 b : tending to forget or fail to notice things : given to absence of mind

Her absentminded husband forgot their anniversary.


I think this is what you are mentioning:

  • 2 indicative of or resulting from preoccupation or absence of mind

gave an absentminded reply


If your brain-fart's usage is similar, I guess the explanation above is good enough.

  • 3
    ど忘れ seems like the closest fit to "brain fart" to me
    – Leebo
    Commented Aug 8, 2019 at 13:29
  • @Leebo Thanks for the information. I guess ど忘れ is not as informal as brain fart at least to me, but I will use them in the future. Commented Aug 8, 2019 at 13:34
  • @leebo You should post that as an answer, it’s also the first thing that came to mind for me. Commented Aug 8, 2019 at 14:38
  • @Leebo That's what immediately came to my mind too. You should post as an answer.
    – istrasci
    Commented Aug 8, 2019 at 15:43

If I'm not having a brain fart, that word can be used when wrong things come out off your head, as well as when nothing comes out.

ど忘れ in @Leebo's answer serves well for the latter case that you can recall nothing normally you should, but cannot cover the situation when you've said something nonsensical because of mental glitch. In that case I think I'd use ぼけて(い)る.

Explained with this Urban Dictionary example:

Person A: Hey, switch on the TV, this show is annoying.
Person B: Switch it ON?
Person A: No, I meant off... I had a brainfart.

ぼける is an informal word to mean you have any kind of dementia, and also for thinko. If you blame for low consciousness (e.g. tired, sleepy...) you can also use 寝ぼける.


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