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

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

However, additional analyses produced similar results even after accounting for factors such as age, sex, previous fractures, previous falls, and average calcium intake from food.

From Science Daily • Jun. 15, 2026

They further suggest that clinicians, guideline panels, and regulatory agencies "should re-evaluate their general recommendations for calcium and vitamin D supplementation in light of current evidence."

From Science Daily • Jun. 15, 2026

It was a simple procedure to scope out the calcium buildup, but the doctor explained I’d be put to sleep with anesthesia.

From "Courage to Soar" by Simone Biles