cel·lu·loid / ˈselyəˌloid/ • n. a transparent flammable plastic made in sheets from camphor and nitrocellulose, formerly used for cinematographic film. ∎  motion pictures as a genre.

celluloid Hard plastic invented (1869) in the USA by John Hyatt. Hyatt made the plastic by mixing cellulose nitrate with pigments and fillers in a solution of camphor and alcohol. When heated, it can be moulded into a variety of shapes and hardens on cooling. It was the first major plastic, and was used for early motion pictures. It is highly flammable.