n. The act or operation of calcining, or expelling from a substance by heat some volatile matter with which it is combined, or which is the cementing principle, and thus reducing it to a friable state.n. In metallurgy: The operation of reducing a metal to an oxid or metallic calx: now called oxidation.n. The process of being calcined, or heated with access of air: nearly equivalent to roasting.n. The process of treating certain ores, especially of iron, for the purpose of making them more manageable in the furnace, nothing being taken from or added to the material thus treated. This is done with some Swedish iron ores.n. The reduction to ashes of combustible substances by burning; a turning into ashes by combustion.n. A calcined state or condition.n. A product of calcination, a calcinate.