Calcium

//ˈkælsi.əm// noun

noun ·Moderate ·College level

Definitions

Noun
  1. 1
    The chemical element with atomic number 20: a soft, silvery-white alkaline earth metal which occurs naturally as carbonate in limestone and as silicate in many rocks. countable, uncountable

    "Oxygen levels on Earth skyrocketed 2.4 billion years ago, when cyanobacteria evolved photosynthesis:[…]. The evolutionary precursor of photosynthesis is still under debate, and a new study sheds light. The critical component of the photosynthetic system is the “water-oxidizing complex”, made up of manganese atoms and a calcium atom."

  2. 2
    a white metallic element that burns with a brilliant light; the fifth most abundant element in the earth's crust; an important component of most plants and animals wordnet
  3. 3
    An atom of this element. countable

Synonyms

All synonyms
atomic number 20cagoldironleadmetal

Example

More examples

"Calcium is absent from his diet."

Etymology

Coined by British chemist Humphry Davy in 1808, from Latin calx (“lime, limestone”) because it occurs in limestone. By surface analysis, calc- + -ium.

Related phrases

bismuth strontium calcium copper oxidecalcium acetatecalcium arsenatecalcium benzoatecalcium bilirubinatecalcium cannoncalcium carbidecalcium carbonatecalcium channel blockercalcium chloridecalcium chromatecalcium copper tetrasilicate

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Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.