Japanese Slang Word: 「鬼〜」 (Oni~)

When studying Japanese, especially if you don’t live in Japan, there are always blind spots which can develop in your learning depending on what materials and methods you use to study. One area that I’ve found difficult is slang, because many of the materials I use (especially books and TV dramas) tend to not use them too often. Slang is a moving target–it can evolve pretty quickly as new popular words are coined and become commonly used by the younger generation.

While I have known about the word 鬼 (‘oni’, which means something like ‘devil’) for some time, it was only recently that I heard there is an alternate slang meaning for this. Here is an example sentence of this usage:

• ”それって鬼ムズじゃない”  [Sore tte oni muzu ja nai]
• Isn’t that like totally difficult?

(In the English translation, I’ve tried to capture the slang nuance in addition to the meaning itself.)

Here, you can see that ‘oni’ is express the extent of something, similar to the English word ‘extremely’. The Japanese word 超 (chou) is also used in a similar manner, though I’ve been told that ‘oni’ is even more extreme than ‘chou’. Another word with similar usage is “激” (geki), though I see/hear that a bit less often.

There is actually a second slang word in the above example, “ムズ” (muzu) which is an abbreviation for ‘muzukashii’ (難しい) and means ‘difficult’.

Originally I thought that ‘oni’ was pretty new slang, but this 2004 post on Oshiete Goo discusses it, and someone says the expression may be around 10 years old. So it seems that it has existed in some form for over two decades. It describes the meaning as “鬼のように。。。” (‘…like a devil’)

There seems to be a pattern with using 鬼 before two-character slang words like in the above example (with ムズ). Another example is ”鬼ムカ” (oni muka) which means “totally irritated”. (ムカ comes from ムカつく that means ‘to be irritated’).

Another one of these is ”鬼ヤバ” (oni yaba) which is basically a curse word.  ヤバ comes from やばい (yabai) which I wrote a post about here.

Keep in mind that pretty much all of these examples, as well as this use of 鬼, are considered impolite (or at least casual) words and should not be used except in very informal situations. I personally don’t have any plans to integrate 鬼 into my vocabulary, except for maybe jokes with close friends.

But even if you don’t use these words yourself, it’s good to be aware of them so they don’t catch you off guard at a critical moment. If you want to see 鬼 used you can find it all over places like Twitter and Youtube. I haven’t written too many posts about slang lately, but if you are curious to learn more please consider liking this article.

As a final note, don’t forget the original meaning for ‘oni’ (devil) is still used in some cases. For example, 鬼ごっこ (oni gokko) which is a children’s game of tag. Here, the word is not slang and shouldn’t be considered impolite.