selenium

From French sélénium, the name coined by Swedish chemist Jöns Jacob Berzelius in 1818 from Ancient Greek σελήνη (selḗnē, “moon”) in reference to original confusion with the similar element tellurium.^[1]

• (UK, US) enPR: sĭlēn′ēəm, səlēn′ēəm, IPA^(key): /sɪˈliːni.əm/, /səˈliːni.əm/

• Audio (General American):

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• Audio (Southern England):

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• Rhymes: -iːniəm

selenium (usually uncountable, plural seleniums)

2. A nonmetallic chemical element (symbol Se) with an atomic number of 34, used mainly in glassmaking and pigments and as a semiconductor.

   Hypernym: chalcogen

   • 2019, Bill Bryson, The Body: A Guide for Occupants, Black Swan (2020), page 4:

     Pluck almost any cell from your body and it will have a million or more selenium atoms in it.

3. A single atom of this element.

• David Barthelmy (1997–2025) “Selenium”, in Webmineral Mineralogy Database.
• “selenium”, in Mindat.org‎^[1], Hudson Institute of Mineralogy, 2000–2025.

• selenium on Wikipedia.Wikipedia

• Melusine, emulsine, semilune, seminule

• Audio:

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selenium (uncountable)

1. synonym of seleen (“selenium”)

• IPA^(key): [ˈsɛlɛːnɪjum]
• Hyphenation: se‧le‧nium

selenium n

1. alternative form of selen

• “selenium”, in Kartotéka Novočeského lexikálního archivu (in Czech)
• “selenium”, in Internetová jazyková příručka (in Czech), 2008–2025

Borrowed from New Latin selēnium, a word coined by Swedish chemist Berzelius in 1818, from Ancient Greek Σελήνη (Selḗnē, “moon”).^[1]

• IPA^(key): /səˈleː.ni.ʏm/, /seːˈleː.ni.ʏm/

• Audio:

  (file)

• Hyphenation: se‧le‧ni‧um

selenium n (uncountable)

1. selenium [from 1818]

   Synonym: seleen

From Ancient Greek Σελήνη (Selḗnē, “moon”) + -ium.

• (Classical Latin) IPA^(key): [sɛˈɫeː.ni.ũː]
• (modern Italianate Ecclesiastical) IPA^(key): [seˈlɛː.ni.um]

selēnium n (genitive selēniī); second declension

1. (New Latin) selenium

Second-declension noun (neuter).

From English selenium, from New Latin, from Ancient Greek Σελήνη (Selḗnē).

• IPA^(key): [selɛniom]
• Rhymes: -iom, -jom, -om

selenium

1. selenium (chemical element)

selenium n (uncountable)

1. alternative form of seleniu