calcium

Coined by British chemist Humphry Davy in 1808, from Latin calx (“lime, limestone”) because it occurs in limestone.^[1] By surface analysis, calc- +‎ -ium.

• (US) IPA^(key): /ˈkælsi.əm/

  • Audio (US):

    (file)

• (Indic) IPA^(key): /ˈkalʃɪəm/
• (Philippines) IPA^(key): /ˈkæl.ʃum/

calcium (countable and uncountable, plural calciums)

2. 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.

   Alternative form: Ca (symbol)

   • 2013 September-October, Katie L. Burke, “In the News”, in American Scientist‎^[1], archived from the original on 30 November 2014:

     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.

   • 2024 August 6, Ricardo Treviño, “Self-Healing Concrete Help Buildings Seal Themselves”, in TecScience‎^[2], archived from the original on 19 January 2025:

     “This material has a specific hardness and is chemically very stable. It forms naturally from calcium alone, but bacteria accelerate the transformation into calcium carbonate,” explains Alejandro Montesinos, head of the Decarbonization, Climate Change, and Circular Economy Research Group at Tec de Monterrey and a member of the Institute of Advanced Materials and Sustainable Manufacturing.

3. (countable) An atom of this element.

• chalk
• lime
• limestone

• Calcium on the British Royal Society of Chemistry's online periodic table

• Calcium in the Encyclopædia Britannica (11th edition, 1911)

• kalcium

From Latin calx +‎ -ium.

calcium n (singular definite calciummet, not used in plural form)

1. calcium

   Coordinate term: kalk

• “calcium” in Den Danske Ordbog

Ultimately from English calcium. Coined by Humphry Davy.

• IPA^(key): /ˈkɑl.siˌʏm/

• Audio:

  (file)

• Hyphenation: cal‧ci‧um

calcium n (uncountable, no diminutive)

1. calcium [from early 19th c.]

• calciumoxide
• calciumzout

• kalk

• IPA^(key): /kal.sjɔm/

• Audio:

  (file)

• Audio (France (Vosges)):

  (file)

• Audio (France (Vosges)):

  (file)

calcium m (uncountable)

1. calcium

• calcaire
• calcifier
• calcique

• Lingala: kalisu

• “calcium”, in Trésor de la langue française informatisé [Digitized Treasury of the French Language], 2012

calcium (uncountable)

1. calcium

• (Classical Latin) IPA^(key): [ˈkaɫ.ki.ũː]
• (modern Italianate Ecclesiastical) IPA^(key): [ˈkal̠ʲ.t͡ʃi.um]

Form of calx.

calcium

1. genitive plural of calx

Derived from calx, calcis (“chalk”) +‎ -ium (chemical element suffix).

calcium n (genitive calciī); second declension

1. (New Latin) calcium

Second-declension noun (neuter).

• → Catalan: calci
• → French: calcium
• → Galician: calcio
• → Italian: calcio
• → Portuguese: cálcio
• → Romanian: calciu
• → Sicilian: cauci, cauciu
• → Spanish: calcio