Breadcrumb Home > Dictionary > Index P prismatoid: Meaning and Definition of Find definitions for: pris•ma•toid Pronunciation: (priz'mu-toid"), [key] — n. Geom. a polyhedron having its vertices lying on two parallel planes. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: prismatoid (Thesaurus) prismatic telescope prism binocular ✖ Related Content Daily Word Quiz: quadrumanous Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language