Etymologically
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iodine

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Pronunciation

  • /ˈaɪ.əˌdaɪn, -dɪn, -diːn/[1]

Etymology

The English chemist Sir Humphry Davy named it in 1814;[2][3][4][5] it is borrowed from French iode (“iodine”) with the chemical suffix -ine, to match chlorine and fluorine.[2][3][4][6] The French name was given in 1812 by the chemist Joseph Louis Gay-Lussac,[3][4][5][2] although Klein credits it to Bernard Courtois, who discovered the element in 1811.[6][4] It is from Ancient Greek ἰώδης (iṓdēs, “violet-coloured”)[2][5][7][8][9] or ἰοειδής (ioeidḗs),[3][4][10][11][1] from ἴον (íon, “violet”) and -ειδής (-eidḗs, “like”), from εἶδος (eîdos, “appearance, form”),[2][3][4][6] after the violet colour of the vapour the crystals give off when heated.[3][4][2] Collins and Dictionary.com, however, take the Greek adjective as originally meaning "rust-coloured", reinterpreted as "violet-like" through a mistaken connection with íon.[12][13] Greek íon, which originally began with a w-, is related to Latin viola, the source of violet;[4][14][10][15] Barnhart and Partridge consider both to be from a non-Indo-European Mediterranean language.[4][14]

Earliest recorded meaning

The chemical element: 1814, in Davy's paper in the Philosophical Transactions of the Royal Society.[2][4][3]

Semantic evolution

The word has kept its chemical sense, and was soon used for the element's preparations as well: from 1843 there was a verb iodine, to treat with iodine or iodize,[2][7] and iodine also names the antiseptic solution, tincture of iodine.[1] Davy's name was the model for later derivatives such as iodoform, formed after chloroform.[9][5] In southern Lincolnshire dialect, iodine was a name for the greater celandine.[16]

Timeline

  • 1812 – French iode named by Gay-Lussac.[3][4][5]
  • 1814 – the element, named by Davy.[2][3][4]
  • 1843 – verb, to treat with iodine.[2]

Meanings

Noun

  1. A nonmetallic chemical element of the halogen group, symbol I, atomic number 53, forming blackish crystals that give off a violet vapour; it is needed by the thyroid and used in medicine, photography and dyes.[12][11][2][7]
  2. A solution of iodine used as an antiseptic: The nurse dabbed iodine on the graze.[1]

Verb

  1. (rare) To treat with iodine; to iodize.[2][7]

Word family

  • povidone-iodine
  • iodimetry
  • iodinate
  • radioiodine
  • quartz-iodine lamp

References

  1. ^ a b c d Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f g h i j k l Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
  3. ^ a b c d e f g h i Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  4. ^ a b c d e f g h i j k l Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
  5. ^ a b c d e Weekley, Ernest (1921), An Etymological Dictionary of Modern English, London: John Murray
  6. ^ a b c Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
  7. ^ a b c d Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
  8. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
  9. ^ a b Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
  10. ^ a b The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
  11. ^ a b Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
  12. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins
  13. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
  14. ^ a b Partridge, Eric (1966), Origins: A Short Etymological Dictionary of Modern English, 4th ed., London: Routledge & Kegan Paul
  15. ^ Ayto, John (2005), Word Origins: The Secret Histories of English Words from A to Z, 2nd ed., London: A & C Black
  16. ^ Wright, Joseph, ed. (1898–1905), The English Dialect Dictionary, 6 vols., Oxford: Henry Frowde; via EDD Online 4.0, University of Innsbruck (CC BY 4.0)