calcium

American  

[kal-see-uhm] / ˈkæl si əm /

noun

Chemistry, Biology.

• calciums
  plural

1. 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 contraction, and many other physiological functions. Ca; 40.08; 20; 1.55 at 20°C.

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calcium British  

/ ˈkælsɪəm /

noun

1. 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 deoxidizer in steel. Symbol: Ca; atomic no: 20; atomic wt: 40.078; valency: 2; relative density: 1.55; melting pt: 842±2°C; boiling pt: 1494°C

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calcium Scientific  

/ kăl′sē-əm /

1. A silvery-white, moderately hard metallic element of the alkaline-earth group that occurs in limestone and gypsum. It is a basic component of leaves, bones, teeth, and shells, and is essential for the normal growth and development of most animals and plants. Calcium is used to make plaster, cement, and alloys. Atomic number 20; atomic weight 40.08; melting point 842 to 848°C; boiling point 1,487°C; specific gravity 1.55; valence 2.

2. See Periodic Table

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Other Word Forms

Noun Inflected Forms

• calciums
  plural

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Etymology

Origin of calcium

First recorded in 1800–10; calc- + -ium

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Example Sentences

See Examples For:

calcium calciums

Their investigation identified a calcium channel in macrophages, the immune cells that engulf bacteria, that becomes activated by titanium particles.

From Science Daily ● Oct. 23, 2026

One of the most striking discoveries was the unusual way statin molecules attach to the calcium channel.

From Science Daily ● Oct. 20, 2026

It is important that teenage girls, especially, get enough iron and calcium, so Ludlam-Raine says not to become overly focused on protein at the expense of other nutrients.

From BBC ● Oct. 15, 2026

He explains that we need micronutrients like zinc, calcium and magnesium, which are found in whole foods.

From BBC ● Oct. 15, 2026

“Yeah. See? The granules are perfectly round. It’s not really sand. It’s calcium carbonate.”

From "The Mark of Athena" by Rick Riordan

The calciums had gradually been turning to the blue of moonlight, and now, at the back of the stage, Venus arose, veiled in a mist of foam.

From The Title Market by J. H. Gardner Soper

It appears to me that one of the calciums had flared up and the sparks ignited the lint on the curtain.

From Chicago's Awful Theater Horror by Various

"I'll take the centre of the stage, and you will order calciums for one!"

From Vignettes of Manhattan; Outlines in Local Color by Brander Matthews

The picture is built up bit by bit; it is never flashed suddenly and completely as by best-seller calciums; it remains a bit dim at the end.

From A Book of Prefaces by H. L. (Henry Louis) Mencken

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