- noun a soft white or colourless mineral consisting of hydrated calcium sulfate, used in cement, plaster and fertilisers
- A naturally occurring, soft, whitish mineral (hydrous calcium sulfate) that, after processing, is used as a retarding agent in Portland cement and as the primary ingredient in plaster, gypsum board, and related products.
Origin & History of “gypsum”
The word gypsum originated among the Semitic languages, with a relative or ancestor of Arabic jibs and Hebrew gephes ‘plaster’. Greek adopted this unknown form as gúpsos, which passed into Latin as gypsum. (An Italian descendant of gypsum is gesso ‘plaster’, borrowed by English in the 16th century for ‘plaster as a surface for painting on’.).