n.
In manufacturing, a cavity or surface in which a fluid or plastic substance is shaped into a desired finished product.
A molten substance, such as metal or plastic, is poured or forced into a mold and allowed to harden. Molds are made of various materials, depending on the application; sand is frequently used for metal casting , hardened steel for molds for plastic materials, and plaster for various purposes. See also ingot , patternmaking , tool and die making .