Hard-boiled film genre (4)
I believe the answer is:
noir
'hard-boiled film genre' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for noir that I've seen before include "film genre" , "Dark in France, like brooding films of 40s and 50s" , "Kind of dark film" , "type of film" , "(Of film or fiction) with bleak settings and cynical characters" .)