/ Dictionary / Index P plateholder: Meaning and Definition of Find definitions for: plate•hold•er Pronunciation: (plāt'hōl"dur), [key] — n. a lightproof container for a photographic plate, loaded into the camera with the plate and having a slide that is removed before exposing. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. plate glass platelet Related Content Daily Word Quiz: loquacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language