The meanings of 神経


I just came across the phrase

> どういう神経だ！  
>  What a nerve! (my translation)

in a book translated from English to Japanese. Because it's a translation I'm
a little doubtful about whether it's correct/idiomatic.

I can think of three meanings of nerve in English:

  1. The biological thingy;
  2. The courage to do something;
  3. The audacity to do something.

The context of the book means that meaning 3) must be intended. Yet when I
look in [weblio](https://www.weblio.jp/content/%E7%A5%9E%E7%B5%8C) and
[kotobank](https://kotobank.jp/word/%E7%A5%9E%E7%B5%8C-81577#E7.B2.BE.E9.81.B8.E7.89.88.20.E6.97.A5.E6.9C.AC.E5.9B.BD.E8.AA.9E.E5.A4.A7.E8.BE.9E.E5.85.B8)
I see nothing that looks like either meaning 2) or 3).

To what extent does 神経 mirror the English meanings?




神経 can appear naturally in non-translated conversations. In a sentence like
this, it refers to someone's common-sense judgment. どういう神経だ (or どんな神経をしているんだ)
may be said after someone said or did something based on an insane judgement.
Courage or audacity is not necessarily relevant, so its meaning may be broader
than "What a nerve!" in English. But 神経が図太い is an idiom that means "to have
strong nerves" or "fearless", so what it actually refers to depends on the
phrase.




神経 can appear naturally in non-translated conversations. In a sentence like
this, it refers to someone's common-sense judgment. どういう神経だ (or どんな神経をしているんだ)
may be said after someone said or did something based on an insane judgement.
Courage or audacity is not necessarily relevant, so its meaning may be broader
than "What a nerve!" in English. But 神経が図太い is an idiom that means "to have
strong nerves" or "fearless", so what it actually refers to depends on the
phrase.

