[jip-suh m]


a very common mineral, hydrated calcium sulfate, CaSO4⋅2H2O, 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.

Origin of gypsum

1640–50; < Latin: chalk < Greek gýpsos chalk, gypsum Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for gypsum

adhesive, cement, glue, mortar, stucco, lime, coat, binding, gum, dressing, paste, mucilage

Examples from the Web for gypsum

Contemporary Examples of gypsum

Historical Examples of gypsum

  • Green and red marl, shale, and shaly limestone with some veins of gypsum.

    Old Mackinaw

    W. P. Strickland.

  • Beds of gypsum have been discovered on the head waters of the Pere Marquette.

    Old Mackinaw

    W. P. Strickland.

  • To every hundred pounds of this powder, about three pounds of gypsum is added.

    Diggers in the Earth

    Eva March Tappan

  • The United States is the largest producer of gypsum in the world.

  • Production of gypsum in the United States comes from eighteen states.

British Dictionary definitions for gypsum



a colourless or white mineral sometimes tinted by impurities, found in beds as an evaporite. It is used in the manufacture of plaster of Paris, cement, paint, school chalk, glass, and fertilizer. Composition: hydrated calcium sulphate. Formula: CaSO 4 .2H 2 O. Crystal structure: monoclinic
Derived Formsgypseous (ˈdʒɪpsɪəs), adjectivegypsiferous (dʒɪpˈsɪfərəs), adjective

Word Origin for gypsum

C17: from Latin, from Greek gupsos chalk, plaster, cement, of Semitic origin
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for gypsum

substance (hydrated calcium sulphate) used in making plaster, late 14c., from Latin gypsum, from Greek gypsos "chalk," according to Klein, perhaps of Semitic origin (cf. Arabic jibs, Hebrew gephes "plaster").

Online Etymology Dictionary, © 2010 Douglas Harper

gypsum in Science



A colorless, white, or pinkish mineral. Gypsum occurs as individual blade-shaped crystals or as massive beds in sedimentary rocks, especially those formed through the evaporation of saline-rich water. It is used in manufacturing plasterboard, cement, and fertilizers. Chemical formula: CaSO4·2H2O.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.