to reduce to a powder, or to a friable state, by the action of heat; to expel volatile matter from by means of heat, as carbonic acid from limestone, and thus (usually) to produce disintegration; as to, calcine bones.-to oxidize, as a metal by the action of heat; to reduce to a metallic calx.-to be converted into a powder or friable substance, or into a calx, by the action of heat.