Plaster of Paris is a powder that forms a paste when mixed with water and then thickens and hardens.(noun)
An example of plaster of Paris is one of the materials used to create a cast for a broken arm.
See plaster of Paris in Webster's New World College Dictionary
Origin: from use of gypsum from Montmartre in Paris in its manufacture
See plaster of Paris in American Heritage Dictionary 4
Origin: Middle English
Origin: , after Paris2, France.
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