What is Film Noir or Noir genre?

Radaghast said:

Yes, noir is French for black, after all.

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But the characters are "dark" too, with dark personalities.
Maybe I said this earlier in the thread, but I read somewhere that in most noir films none of the characters are really likable.
You really don't really root for any of them.
A great example of this is all the characters in Chinatown.