ENGLISH
REFERENCE

calcium

n.
US //ˈkæɫsiəm// UK //kˈælsiəm// cal·ci·um
  1. 1 the mineral for health (n.)
    B2 Upper Intermediate Medicine

    a substance found in foods like milk and cheese that helps you grow strong bones and teeth.

    the chemical element considered as a dietary mineral essential for the maintenance of skeletal structure and various physiological functions.

    Example

    Drinking milk is a good way to get enough calcium for your bones.

    Example

    A diet deficient in calcium during adolescence can lead to decreased bone density and a higher risk of fractures in later life.

    Usage

    Usually uncountable when referring to the nutrient in food or the body.

  2. 2 the chemical element (n.)
    C1 Advanced Technical Science

    a soft, silver-white metal that is found in rocks like limestone.

    the alkaline earth metal with atomic number 20, occurring naturally in compounds such as limestone, gypsum, and fluorite.

    Example

    The scientist explained that calcium is a very reactive metal in its pure form.

    Example

    In its elemental state, calcium is a silvery-white metal that reacts steadily with water to form calcium hydroxide and hydrogen gas.

Origin

Coined by British chemist Humphry Davy in 1808, from Latin calx (“lime, limestone”) because it occurs in limestone. By surface analysis, calc- + -ium.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Last updated June 20, 2026