calcium

noun

cal·​ci·​um ˈkal-sē-əm How to pronounce calcium (audio)
often attributive
: a metallic chemical element of the alkaline-earth group that occurs naturally only in combination and is essential to cellular functions in all known organisms see Chemical Elements Table

Examples of calcium in a Sentence

Her doctor said she should eat more foods that are high in calcium, such as milk and cheese.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
In the alkaline stream, calcium in the seawater converts CO₂ into calcium carbonate, the durable compound seashells are made of. — Alec Luhn, Scientific American, 20 Oct. 2026 Once applied, the gel forms a thin layer over the tooth that acts like a scaffold, guiding calcium and phosphate from saliva into new crystals that follow the structure of the enamel underneath. — Ryan Brennan, Miami Herald, 20 Oct. 2026 That’s the idea behind familiar ingredients like fluoride, as well as newer formulas built around calcium, phosphate or hydroxyapatite. — Ryan Brennan, Fort Worth Star-Telegram, 20 Oct. 2026 Scientists at the University of Oxford developed a quantum network using two different atoms, strontium and calcium, and achieved a record entanglement time of 10 seconds. — Ameya Paleja, Interesting Engineering, 19 Oct. 2026 See All Example Sentences for calcium

Word History

Etymology

New Latin, from Latin calc-, calx lime

First Known Use

1808, in the meaning defined above

Time Traveler
The first known use of calcium was in 1808

Phrases Containing calcium

Rhymes for calcium

See All Rhymes for calcium

Browse Nearby Words

calcitrate
calcium
calcium aluminate
See all Nearby Words

Cite this Entry

“Calcium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/calcium. Accessed 22 Oct. 2026.

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Kids Definition

calcium

noun
cal·​ci·​um ˈkal-sē-əm How to pronounce calcium (audio)
: a silver-white soft metallic element that is found only in combination with other elements (as in limestone) and is one of the necessary elements making up the bodies of most plants and animals see element
Etymology

derived from Latin calc-, calx "lime" — related to calculate, chalk

Medical Definition

calcium

noun
cal·​ci·​um ˈkal-sē-əm How to pronounce calcium (audio)
often attributive
: a silver-white bivalent metallic element that is an alkaline earth metal, occurs only in combination, and is an essential constituent of most plants and animals
—symbol Ca see Chemical Elements Table

More from Merriam-Webster on calcium

Britannica.com: Encyclopedia article about calcium

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