Real Dictionary

calcium in American English
a soft, silver-white, metallic chemical element, one of the alkaline-earth metals, found in limestone, marble, chalk, etc., always in combination: it is used as a reducing agent and in fertilizer, and is the essential part of bones, shells, and teeth: sym
noun: a silver-white divalent metal, occurring combined in limestone, chalk, gypsum, etc., occurring also in vertebrates and other animals, as a component of bone, skeletal mass, shell, etc., and as a necessary element in nerve conduction, heartbeat, muscle con

calcium in British English
noun: a malleable silvery-white metallic element of the alkaline earth group; the fifth most abundant element in the earth's crust (3.6 per cent), occurring esp as forms of calcium carbonate. It is an essential constituent of bones and teeth and is used as a de