Breadcrumb Home > Dictionary > Index G gypsum plaster: Meaning and Definition of Find definitions for: gyp'sum plas"ter Pronunciation: [key] plaster made primarily of gypsum. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. gypsum board Gypsy ✖ Related Content Daily Word Quiz: nabob Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language