Yesterday, I found myself cringing at an article by an entertainment writer who kept using the term "film noir" as if it was the latest hip word needed to validate that writer's knowledge of the film industry. The phrase was abused, mis-used, and over-used. So, I looked up some definitions of film noir and found a couple of links that were interesting. I welcome more links or better definitions.
film noir - a movie characterized by low-key lighting, a bleak urban setting, and corrupt, cynical characters.
film noir - Originally a French term (literally "black film"), now in common usage, to indicate a film with a gritty, urban setting that deals mainly with dark or violent passions in a downbeat way. Especially common in American cinema during the late forties and early fifties, its themes of existential alienation and paranoia have often been read as signs of postwar malaise and Cold War anxiety. James Monaco's Film Glossary
film noir - shadowy, pessimistic movie: a cinematic genre popular in the 1940s and 1950s, often filmed in urban settings with extensive use of shadows, cynical in outlook, and featuring antiheroes.
film noir - a type of crime film featuring cynical malevolent characters in a sleazy setting and an ominous atmosphere that is conveyed by shadowy photography and foreboding background music; also : a film of this type. Merriam Webster Online
The Development of Post-war Literary and Cinematic Noir
High Heels on Wet Pavement