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

Etymology

Origin of calcium

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

Example Sentences

See Examples For:

calcium calciums

The researchers found that curcumin treatment appeared to reduce inflammation and restore more normal calcium activity in blood vessels.

From Science Daily ● Aug. 26, 2026

The material draws calcium and phosphate ions from saliva and uses them to guide the controlled formation of new mineral crystals.

From Science Daily ● Jul. 23, 2026

Chandra's X-ray observations highlight the powerful blast wave from the stellar explosion and reveal elements scattered throughout the debris, including iron, calcium, and oxygen.

From Science Daily ● Jul. 4, 2026

Taking a cocktail of iron, calcium and magnesium together can reduce absorption rates.

From BBC ● Jun. 20, 2026

Soon after taking up his position, Davy began to bang out new elements one after another–potassium, sodium, magnesium, calcium, strontium, and aluminum or aluminium, depending on which branch of English you favor.*

From "A Short History of Nearly Everything" by Bill Bryson

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 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

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