plaster of paris
plaster of par·is
noun \-ˈpar-əs\Definition of PLASTER OF PARIS
: a white powdery slightly hydrated calcium sulfate CaSO4·1⁄2H2O or 2CaSO4·H2O that is made by calcining gypsum, forms a quick-setting paste with water, and is used in medicine chiefly in casts and for surgical bandages
