selenium

Etymology

It is borrowed from New Latin selenium,^[2][3][4][5] named in 1818 by its discoverer, the Swedish chemist Jöns Jakob Berzelius.^[2][4][6][3] He formed it from Ancient Greek σελήνη (selḗnē, “moon”) (in Doric σελάνα (selā́nā)) and -ium,^[4][7][5][2] and the Greek word comes from σέλας (sélas, “light, brightness”),^[7][4] of unknown origin according to Barnhart.^[4] Etymonline, under Selene, relates sélas to Proto-Indo-European *swel- (“to shine”).^[3] The name marked the new element's resemblance to tellurium, named after the earth from Latin tellūs (“earth”),^{[2][8][9][4][6]} with which, according to Etymonline, it had at first been confused.^[3] Compare German Selen.^[2]

Earliest recorded meaning

The chemical element: 1818, in a translation of Berzelius in the Annals of Philosophy;^[2][8] Berzelius explained the choice of name in the Journal für Chemie und Physik the same year.^[2][8]

Semantic evolution

Like tellurium, selenium was at first classed among the metals but is now regarded as a non-metal.^[2] Etymonline notes that for this reason its -ium ending is misleading, and that the more fitting name selenion has been proposed.^[3]

Timeline

• 1818 – the chemical element.^[2][8][4]

Meanings

Noun

1. A nonmetallic chemical element, atomic number 34, symbol Se, chemically close to sulfur and tellurium, occurring in several forms; its grey form conducts electricity much better in light than in darkness, which makes it useful in photocells, solar cells and xerography.^{[9][10][8][2]}

Word family

• selenious
• selen-
• selenate
• selenide
• seleniferous
• seleno-
• selenite
• selenous

Related words

• tellurium
• Selene

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c d e f g Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
5. ^ a b Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
6. ^ a b Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
7. ^ a b The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
8. ^ a b c d e Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
9. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins
10. ^ The American Heritage Dictionary of the English Language (1992), 3rd ed., Boston: Houghton Mifflin