n. A very thin skin or membrane; a pellicle; an attenuated layer, lamina, or sheet of any substance: as, a membranous or watery film over the eye; a film of oil or gelatin; a film of lace, gauze, etc.; a film of air between two plates.n. Specifically In photography: The coating on a plate mechanically and chemically prepared to serve as a medium for taking a picture, either before or after it has been sensitized: as, the collodion film of the wet plate, or the gelatin film of the dry plate.n. A skin or film, usually composed in great part of gelatin, made to serve as a medium for receiving a picture, as that described undern. but so prepared as to be independent of any supporting plate, or to admit of being stripped intact from such a plate.n. A fine thread, as of a cobweb.To cover with a film, or thin skin or pellicle.To become covered by a film; become obscured, as if covered by a film.