Etymologically
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thyroid

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Pronunciation

  • /ˈθaɪ.ɹɔɪd/[1]

Etymology

It is borrowed from New Latin thyroidēs,[2][3][4][5] or Middle French thyroide, now French thyréoïde,[4][5][6] from an irregular or altered form of Ancient Greek θυρεοειδής (thureoeidḗs, “shield-shaped”),[5][7][4][6] which Galen used in χόνδρος θυρεοειδής (khóndros thureoeidḗs, “shield-shaped cartilage”) for the cartilage that forms the Adam's apple.[6][8][7][9] The Greek adjective is formed from θυρεός (thureós, “oblong shield; stone put against a door”), from θύρα (thúrā, “door”),[6][10][11][12] and -οειδής (-oeidḗs, “-like”).[10][11] The Greek word for "door" is related to door, and goes back to Proto-Indo-European *dhwer- (“door, doorway”).[8][7][12]

Earliest recorded meaning

Shield-shaped, of the largest cartilage of the larynx and of the gland beside it: Barnhart finds thyroides in 1693, in a translation from French,[13] and Etymonline dates it to the 1690s, used of both the cartilage and the gland.[8] The OED's and Barnhart's 1988 first record is in Monro's Anatomy (1726–41).[6][11]

Semantic evolution

In English the adjective was applied from the start to both the cartilage and the gland;[8][6] from 1828 it was also used of the arteries, nerves and veins connected with them.[6] As a noun, thyroid was short for the thyroid cartilage from 1840 and for the thyroid gland from 1849–52;[6][11][8] it was also used for thyroid extract,[6] a powder made from animals' thyroid glands and formerly much used to treat hypothyroidism.[2][14] In zoology it described a shield-shaped colour marking (1891), and in botany it meant shield-like (1900).[6] The combining form is thyro-.[8]

Timeline

  • 1693 – thyroides, in a translation from French (Barnhart).[13]
  • 1726–41 – of the thyroid cartilage and gland, in Monro's Anatomy.[6][11]
  • 1828 – of the arteries, nerves and veins near them.[6]
  • 1840 – noun, the thyroid cartilage.[6][11]
  • 1849–52 – noun, the thyroid gland.[6][11]
  • 1891 – in zoology, of a shield-shaped marking.[6]

Meanings

Noun

  1. The thyroid gland, a large endocrine gland at the base of the neck: Her doctor ordered a scan of her thyroid.[3][2][6]
  2. Thyroid extract, a preparation from the thyroid glands of animals, used to treat hypothyroidism.[2][14][6]
  3. The thyroid cartilage, the largest cartilage of the larynx.[6][2]

Adjective

  1. Of, relating to or caused by the thyroid gland: a thyroid disorder.[2][3]
  2. Of or relating to the largest cartilage of the larynx.[2][6]
  3. Shaped like a shield, in anatomy, zoology or botany.[3][6][14]

Word family

  • thyroidal
  • thyroidless
  • hyperthyroidism
  • hypothyroidism
  • thyro-
  • thyr-
  • euthyroid
  • antithyroid

References

  1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f g Collins English Dictionary (2023), Glasgow: HarperCollins
  3. ^ a b c d Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
  4. ^ a b c Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
  5. ^ a b c Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
  6. ^ a b c d e f g h i j k l m n o p q r s t Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
  7. ^ a b c Ayto, John (2005), Word Origins: The Secret Histories of English Words from A to Z, 2nd ed., London: A & C Black
  8. ^ a b c d e f Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  9. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
  10. ^ a b Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
  11. ^ a b c d e f g Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
  12. ^ a b The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
  13. ^ a b Barnhart, Robert K., ed. (1995), The Barnhart Concise Dictionary of Etymology, New York: HarperCollins
  14. ^ a b c Stedman's Medical Dictionary, Baltimore: Lippincott Williams & Wilkins