Breadcrumb Home > Dictionary > Index G gypsum: Meaning and Definition of Find definitions for: gyp•sum Pronunciation: ( jip'sum), [key] — n. a very common mineral, hydrated calcium sulfate, CaSO&multiplydot;2HO, occurring in crystals and in masses, soft enough to be scratched by the fingernail: used to make plaster of Paris, as an ornamental material, as a fertilizer, etc. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: gypsum (Thesaurus) gypster gypsum board TrendingHere are the facts and trivia that people are buzzing about. Who's Who in the "Lord of the Rings" Roman Catholic Church Hierarchy Current Events This Week: March 2023 42 Top Western Movie Quotes Slaves in the Family User's Guide to Environmental Language ✖ Related Content Daily Word Quiz: tangential Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language