Etymograph

English

hypothyroidism

Hypothyroidism comes from Ancient Greek θῠρεοειδής ‘Shield-shaped’, from Proto-Indo-European *wéydos ‘seeing’, and ultimately from *weyd- ‘to see’.

  1. Proto-Indo-Europeanc. 4500–2500 BCE*weyd-1‘to see’reconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*wéydos1‘seeing’reconstructed
  3. Proto-Hellenicc. 2200–1600 BCE*wéidos1reconstructed
  4. Ancient Greekc. 800–300 BCEεἶδος1eîdos
  5. Ancient Greekc. 800–300 BCEθῠρεοειδής1thŭreoeidḗs‘Shield-shaped’
  6. New Latinmodernthyreoīdēs1
  7. English1500–presentthyroid1
  8. Englishtodayhypothyroidism1

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, English hypothyroidism

Lineage

  1. Proto-Indo-Europeanc. 4500–2500 BCE*weyd-Wiktionary, English hypothyroidism‘to see’reconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*wéydosWiktionary, English hypothyroidism‘seeing’reconstructed
  3. Proto-Hellenicc. 2200–1600 BCE*wéidosWiktionary, English hypothyroidismreconstructed
  4. Ancient Greekc. 800–300 BCEεἶδοςWiktionary, English hypothyroidismeîdos
  5. Ancient Greekc. 800–300 BCEθῠρεοειδήςWiktionary, English hypothyroidismthŭreoeidḗs‘Shield-shaped’
  6. New LatinmodernthyreoīdēsWiktionary, English hypothyroidism
  7. English1500–presentthyroidWiktionary, English hypothyroidism
  8. EnglishtodayhypothyroidismWiktionary, English hypothyroidism

Formed from hypo- ‘under’ + thyroid + -ism

Proto-Indo-European *upó ‘under, below’

Ancient Greek ὑπό ‘under’

English hypo-

Proto-Indo-European *dʰwer- ‘door’

…

Ancient Greek θῠ́ρᾱ ‘door’

Ancient Greek θῠρεός ‘an oblong shield’

Ancient Greek θῠρεοειδής ‘shield-shaped’

New Latin thyreoīdēs ‘Shaped like a shield’

English thyroid

The story

Coined c. between 1900 and 1905 from hypo- (‘under’) + thyroid + -ism.

Full etymology on Wiktionary

Linked words

through Proto-Indo-European *weyd- ‘to see’

story, guy, video, idea, review, evidence, visit, provide, advice, interview, guide, witness, vision, historic, wisdom, invisible, visa, wit, advise, wizard, evident, historian, visibility, vista, witty, wisely, prudent, revise, guise, envious, prudence, revue, unwise, purview, druid, improvise, vide, twit, avis, voyeur, 104 more

through Proto-Indo-European *wéydos ‘seeing’

wise, 48 more

through Proto-Hellenic *wéidos

eidolon, steroidal, 48 more

through Ancient Greek εἶδος

idol, tabloid, steroid, idyll, trapezoid, colloid, hyoid, sigmoid, 50 more

through Ancient Greek θῠρεοειδής ‘Shield-shaped’

thyroid, 14 more

through English thyroid

parathyroid, thyroxine, hyperthyroidism, thyroiditis, 14 more

Today it means

noun The disease state caused by insufficient production of thyroid hormone by the thyroid gland.

Sources

Sources: Wiktionary, “hypothyroidism”. By Wiktionary contributors, CC BY-SA 4.0, via kaikki.org (dump of Oct 3 2026); text adapted and restructured. Language periods are conventional ranges, not dates for this word. License.

Etymograph / Proto-Indo-European *weyd- / hypothyroidism

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