# plaster of Paris

> English word · Noun

## Definitions
1. A hemihydrate of calcium sulfate, made by calcining gypsum, that hardens when moistened and allowed to dry; used to make casts, molds and sculpture.

## Etymology
So named after a large gypsum deposit at Montmartre, Paris.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/plaster-of-paris