The term 'gritty film genre' is often used to describe the NOIR genre, which is a type of crime drama that emerged in the 1940s. NOIR films typically feature dark and morally ambiguous characters, as well as themes of crime, corruption, and moral ambiguity. They are often set in urban environments and feature a lot of violence and suspense. NOIR films often have a dark and cynical tone, and they often focus on the struggles of the protagonist against a corrupt system.