Gypsum

Part of speech: noun

Pronunciation: /ˈd͡ʒɪp.səm/

Definitions

1. A soft mineral composed of calcium sulfate that is primarily used in building materials and agriculture
2. A naturally occurring sulfate mineral significant for its applications in plaster, drywall, and soil enhancement
3. A naturally found mineral made of calcium sulfate that is soft and widely used in construction and farming

Etymology: Ancient Greek "gúpsos" was the name for chalk, plaster, and the mineral we now call gypsum, and it gave English one of its more surprising pairs of cousins. "Gesso," the white plaster ground that Renaissance painters spread on panels before applying paint, came into English from Italian and descends from the same Greek word. Two words that look nothing alike in use, one a mineral and one a painter's primer, are simply the same material reached by different routes. The route to English ran through Latin. The Romans borrowed the Greek word as "gypsum," and the Latin term passed into English as the name for the mineral. The chemical sense, a hydrated calcium sulfate, is the modern scientific meaning, and the mineral has been used since antiquity for plaster and mortar, which explains why its name was attached to a building material long before anyone analysed its composition.