calcium

noun

cal·​ci·​um ˈkal-sē-əm 

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

Enhance Soil Fertility Rely on the soil sample analysis to determine the levels of phosphorus, potassium, calcium, magnesium, zinc, manganese, and boron in your soil. —Mary Marlowe Leverette, Southern Living, 10 Sep. 2025

For some patients, other tools—like a coronary calcium scan, which can directly show whether there’s silent plaque in the arteries—may be more useful. —Sarah Garone, Health, 9 Sep. 2025

The team used genetic tools, calcium imaging and optogenetics to identify how these two gas pedal/brake hormones operate differently during REM and non-REM sleep. —New Atlas, 8 Sep. 2025

Both are lower in fat than their counterparts but high in calcium and protein. —Bethany Thayer, Freep.com, 6 Sep. 2025

Word History

Etymology

New Latin, from Latin calc-, calx lime

First Known Use

1808, in the meaning defined above

Phrases Containing calcium

• calcium carbide
• calcium carbonate
• calcium channel blocker
• calcium chloride
• calcium citrate
• calcium cyanamide
• calcium gluconate
• calcium hydroxide
• calcium hypochlorite
• calcium oxalate
• calcium oxide
• calcium phosphate
• calcium silicate
• calcium sulfate

Rhymes for calcium

• dicalcium
• tricalcium

Kids Definition

calcium

noun

cal·​ci·​um ˈkal-sē-əm 

: 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 

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