Definition of celluloid

• highly flammable substance made from cellulose nitrate and camphor; used in e.g. motion-picture and X-ray film; its use has decreased with the development of nonflammable thermoplastics
• a medium that disseminates moving pictures; "theater pieces transferred to celluloid"; "this story would be good cinema"; "film coverage of sporting events"
• artificial as if portrayed in a film; "a novel with flat celluloid characters"