/ Dictionary / Index C celluloid: Meaning and Definition of Find definitions for: cel•lu•loid Pronunciation: (sel'yu-loid"), [key] — n. a tough, highly flammable substance consisting essentially of cellulose nitrate and camphor, used in the manufacture of motion-picture and x-ray film and other products. motion-picture film. —adj. of or involving motion pictures. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: celluloid (Thesaurus) cellulitis cellulolytic Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language