noun, often attributive
cal·​ci·​um | \ˈkal-sē-əm \

Definition of calcium 

: a silver-white divalent metallic element of the alkaline-earth group occurring only in combination — 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

That study concluded that vitamin D and calcium combine to reduce the risk of colon cancer. Bradley J. Fikes,, "Vitamin D associated with lower risk of breast cancer, UCSD-led study finds," 15 June 2018 That additional acidity can leach calcium from the corals, making them brittle and unable to grow. Avery Thompson, Popular Mechanics, "How Things Got So Bad for the Great Barrier Reef," 25 Oct. 2018 The first and most promising protein, aequorin, was later used as an indicator for calcium. Harrison Smith, The Seattle Times, "Osamu Shimomura, atomic blast survivor and Nobel-winning chemist, dies at 90," 23 Oct. 2018 With some elevations reaching up to 5,000 feet, the dirt here is alkaline and calcium rich, and being on some of the flattest, most sweeping land in the country adds a sense of romance to the region. Todd Plummer, Vogue, "Beyond Napa: 7 Emerging American Wine Regions to Visit Now," 29 Aug. 2018 Unfortunately, lead resembles calcium so the body treats it as such. Georeen Tanner, Fox News, "Lead may be making Newark’s water poisonous," 17 Aug. 2018 Young girls and women were more likely to report using iron, calcium, multivitamins and vitamin B. Young boys and men were more likely to report using omega-3 fatty acids and body building supplements. Alexandra Sifferlin, Time, "A Third of Children Use Dietary Supplements. Here’s Why Researchers Say That’s Concerning," 18 June 2018 Blood levels of potassium and calcium, for example, have narrow ranges of normal, and falling outside those ranges can be catastrophic. Emily Sohn, Washington Post, "Even if a medical test shows an abnormality, you may not need to worry about it," 3 June 2018 Add more lean or plant-based protein and ingredients loaded with vitamin D and calcium, including small amounts of full-fat dairy. Carly Graf, Outside Online, "The Foods You Should Be Eating at Every Age," 28 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'calcium.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of calcium

1808, in the meaning defined above

History and Etymology for calcium

New Latin, from Latin calc-, calx lime

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Statistics for calcium

Last Updated

7 Dec 2018

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Time Traveler for calcium

The first known use of calcium was in 1808

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More Definitions for calcium



English Language Learners Definition of calcium

: a substance that is found in most plants and animals and that is especially important in people for strong healthy bones


cal·​ci·​um | \ˈkal-sē-əm \

Kids Definition of calcium

: a silvery soft metallic chemical element that is essential for strong healthy bones


noun, often attributive
cal·​ci·​um | \ˈkal-sē-əm \

Medical Definition of calcium 

: 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

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More from Merriam-Webster on calcium

Spanish Central: Translation of calcium

Nglish: Translation of calcium for Spanish Speakers

Britannica English: Translation of calcium for Arabic Speakers Encyclopedia article about calcium

Comments on calcium

What made you want to look up calcium? Please tell us where you read or heard it (including the quote, if possible).


living or existing for a long time

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