thyroid

English

Alternative forms

• thyreoid

Etymology

Etymology tree

Proto-Indo-European *dʰwer-der.

Proto-Hellenic *tʰurā

Ancient Greek θῠ́ρᾱ (thŭ́rā)

Ancient Greek -εος (-eos)

Ancient Greek θῠρεός (thŭreós)

Proto-Indo-European *weyd-

Proto-Indo-European *-os

Proto-Indo-European *wéydos

Proto-Hellenic *wéidos

Ancient Greek εἶδος (eîdos)

Proto-Indo-European *-os

Proto-Indo-European *-s

Proto-Indo-European *-ēs

Proto-Hellenic *-ēs

Ancient Greek -ης (-ēs)

Ancient Greek -ειδής (-eidḗs)

Ancient Greek θῠρεοειδής (thŭreoeidḗs)bor.

New Latin thyreoīdēsbor.

English thyroid

Borrowed from New Latin thyreoīdēs, borrowed from Ancient Greek θῠρεοειδής (thŭreoeidḗs, “shield-shaped”), from θῠρεός (thŭreós, “oblong shield”, from θύρα (thúra, “door”)) + -ειδής (-eidḗs, “-form”).

By surface analysis, Ancient Greek θῠρεός (thŭreós) +‎ -oid = thyro- +‎ -id = Ancient Greek θῠρεός (thŭreós) +‎ -o- +‎ -id.

Pronunciation

• IPA^(key): /ˈθaɪ.ɹɔɪd/

• Audio (Southern England):

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• Audio (US):

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• Rhymes: -aɪɹɔɪd

Adjective

thyroid (not comparable)

1. (anatomy) Of, relating to, or being the thyroid cartilage.
2. (anatomy) Of, relating to, or being the thyroid gland.
   1. Suggestive of a disordered thyroid gland.

      a thyroid personality

3. (botany) Shield-shaped; peltiform.

Derived terms

• antithyroid, anti-thyroid
• cricothyroid
• dysthyroid
• euthyroid
• extrathyroid
• hyperthyroid
• hyperthyroidism
• hypothyroid
• hypothyroidism
• intrathyroid
• low thyroid
• nonthyroid
• parathyroid
• sternothyroid
• thyroid artery
• thyroid cartilage
• thyroid eye disease
• thyroid gland
• thyroidless
• thyroid panel
• thyroid storm
• thyro-, thyr-
• underactive thyroid
• Wilson's thyroid syndrome

Translations

referring to the thyroid gland

• Azerbaijani: qalxanabənzər
• Belarusian: шчытападо́бны (ščytapadóbny)
• Bulgarian: щитовиден (štitoviden)
• Catalan: tiroïdal (ca)
• Chinese:

  Mandarin: 甲狀腺的 / 甲状腺的, 甲狀腺的 / 甲状腺的 (jiǎzhuàngxiàn de)

• Finnish: kilpirauhas- (fi)
• French: thyroïde (fr), thyréoïde (fr)
• Hungarian: pajzsmirigy-
• Ido: tiroida (io)
• Irish: tíoróideach
• Italian: tiroide (it)
• Latin: thyreoīdēs
• Marathi: थायरॉइड (thāyrŏiḍ), अवटु (avṭu)
• Persian: سپردیس (fa) (separdis), تیروئید (fa) (tiro'id)
• Piedmontese: tiròide f
• Polish: tarczycowy (pl)
• Portuguese: tiroide (pt)
• Russian: щитови́дный (ru) (ščitovídnyj)
• Spanish: tiroides (es)
• Tajik: сипаршакл (tg) (siparšakl)
• Thai: ไทรอยด์ (th)
• Ukrainian: щитоподі́бний (ščytopodíbnyj)

Noun

thyroid (plural thyroids)

1. (anatomy) Ellipsis of thyroid cartilage.
2. (anatomy) Ellipsis of thyroid gland.
   • 2013 August 9, Douglas Main, “Israel Outlaws Water Fluoridation”, in Live Science‎^[1], archived from the original on 10 June 2026:

     Israel is one of the few countries that widely fluoridates, besides the United States, Canada, Ireland, New Zealand and Australia. Fluoridation, the addition of fluoride to public drinking water supplies to reduce cavities, is the subject of intense controversy, especially outside of the United States. But opposition to the practice, on the grounds that fluoride has adverse effects on the thyroid, brain and bones, and is an unethical form of mass-medication, appears to be growing.

   1. (medicine) An extract prepared from the thyroid gland of animals and used in treating deficiency of thyroid hormones.

Derived terms

• athyroidism
• dysthyroidism
• thyroidal
• thyroideal
• thyroidectomy
• thyroid hormone
• thyroiditis
• thyroidization
• thyroidologist
• thyroidopathy
• thyroidotomy
• thyroid-stimulating hormone

References

• “thyroid”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.
• “thyroid”, in Merriam-Webster Online, Springfield, Massachusetts: Merriam-Webster, Inc., 1996–present.

Anagrams

• Hydriot