Dictionary.com
Thesaurus.com
Synonyms

gypsum

American  
[jip-suhm] / ˈdʒɪp səm /

noun

  1. a very common mineral, hydrated calcium sulfate, CaSO 4 ⋅2H 2 O, 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.

gypsum British  
/ ˈdʒɪpsəm, dʒɪpˈsɪfərəs, ˈdʒɪpsɪəs /

noun

  1. 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

"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
gypsum Scientific  
/ jĭp′səm /

  1. 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: CaSO 4 ·2H 2 O.

Other Word Forms

  • gypseous adjective
  • gypsiferous adjective

Etymology

Origin of gypsum

1640–50; < Latin: chalk < Greek gýpsos chalk, gypsum

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

For the rest of the building is disappointingly lackluster—boxy white galleries and corridors in “painted gypsum board,” i.e., sheetrock.

From The Wall Street Journal • Dec. 17, 2025

Additionally, the basin was filled with layers of salt and gypsum.

From Science Daily • Oct. 8, 2025

The best remedy for high pH, Wallace said, is to add gypsum to your soil and avoid things that can make the soil more alkaline, such as crushed concrete.

From Los Angeles Times • Apr. 24, 2025

It is a mineral used to make types of plaster which coat our homes, schools and offices - and in Cumbria sits the world's deepest gypsum mine.

From BBC • Feb. 16, 2025

He also brought back sacks of gypsum, and Mom mixed it with water to make Venus de Milo sculptures from a rubber cast she ordered through the mail.

From "The Glass Castle" by Jeannette Walls

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.