The term 'dark film genre, informally' can be summed up as 'NOIR, ' a four-letter word. NOIR is a French term meaning 'BLACK' and is used to describe a genre of crime films that emerged in the 1940s. These films typically feature dark themes, such as crime, corruption, and moral ambiguity. NOIR films often have a cynical tone and feature characters who are morally ambiguous or corrupt. The genre has been influential in many other genres, including neo-NOIR, which is a modern take on the classic NOIR style.