/ Dictionary / Index P prism: Meaning and Definition of Find definitions for: prism Pronunciation: (priz'um), [key] — n. a transparent solid body, often having triangular bases, used for dispersing light into a spectrum or for reflecting rays of light. a solid having bases or ends that are parallel, congruent polygons and sides that are parallelograms. a form having faces parallel to the vertical axis and intersecting the horizontal axes. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: prism (Thesaurus) prisiadka prismatic Related Content Daily Word Quiz: jovial Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language