thyroid, a. (n.)
(ˈθaɪərɔɪd)
Also 9 thyreoid (in Dicts.).
[Etymologically thyreoid, ad. Gr. θυρεοειδής shield-shaped (in Galen χόνδρος θυρεοειδής thyroid cartilage), f. θυρεό-ς oblong shield + -ειδής: see -oid. Cf. obs. F. thyroide (Paré, 16th c.), mod.F. thyréoïde.]
A. adj. Having the form of a shield, shield-shaped: applied to various natural structures (and hence transf. to others connected with them).
1. Anat. a. thyroid cartilage: the largest of the cartilages of the larynx, consisting of two broad quadrilateral plates united in front at an angle, forming the projection in front of the throat known (in men) as ‘Adam's apple’; within the angle are attached the vocal cords.
| [1693 tr. Blancard's Phys. Dict. (ed. 2), Thyroides, the Cartilage, called Scutiformis, of the Larynx.] 1726–41 Monro Anat. (ed. 3) 163 Into this Concavity the Thyroid Cartilage is received. 1808 Barclay Muscular Motions 498 The larynx is partly composed of five cartilages, which are the cricoid, thyroid, the two arytænoid, and the epiglottis. 1854 Bushnan in Orr's Circ. Sc. I. Org. Nat. 121 The thyroid cartilage is wrapped round the essential parts of the larynx. 1857 Dunglison Med. Lex., Thyroid, Thyreoid. |
b. thyroid gland (also called
thyroid body): one of the so-called ‘ductless glands’, a very vascular body adjacent to the larynx and upper part of the trachea in vertebrates.
| [1693 tr. Blancard's Phys. Dict. (ed. 2), Thyroideæ Glandulæ, two, of a viscous..Substance,..situate about the lower seat of the Larynx.] 1726–41 Monro Anat. (ed. 3) 163 The lymphatic Vessel..is..sent from the thyroid Gland. 1727–41 Chambers Cycl. s.v. Thymus, Mr. Cheselden observes, that where the thymus in men is very small, the thyroid glands increase proportionably. 1830 R. Knox Béclard's Anat. 240 Formless fibro-cartilages occur in some compound tumours of the thyroid body. 1872 Huxley Phys. v. 126 The thyroid gland..is that organ which when enlarged by disease gives rise to ‘Derbyshire neck’ or ‘goitre’. 1899 L. Hill Man. Hum. Physiol. xxvi. 301 If a cretin be fed on thyroid glands taken from sheep his condition is improved... It is clear then that the thyroid gland produces a material necessary for the growth of the body. |
c. Applied to various structures connected with the thyroid cartilage or gland, as the
thyroid arteries,
thyroid nerves,
thyroid veins, etc.
thyroid axis, a branch of the subclavian artery, distributed to the thyroid gland and adjacent parts. (See also B. 2 b.)
| 1831 R. Knox Cloquet's Anat. 746 Right Inferior Thyroid Vein..similar to the left, with which it constitutes the thyroid venous plexus. 1840 E. Wilson Anat. Vade M. (1842) 271 The Superior Thyroid Artery curves downwards to the thyroid gland to which it is distributed. 1878 T. Bryant Pract. Surg. I. 104 Thyroid cysts may be tapped in the same way as the cervical. 1881 Mivart Cat 209 The second branch given off from the subclavian..is the thyroid axis. |
d. thyroid foramen,
thyroid membrane: names for the obturator foramen and membrane of the hip-bone (see
obturator 1), from their shield-like shape.
| 1890 Billings Nat. Med. Dict., T[hyroid] foramen, obturator foramen. |
2. Zool. Applied to a shield-shaped colour-marking, or
transf. to a bird having such a marking, as the thyroid woodpecker,
Sphyropicus thyroideus.
3. Bot. ‘Shield-like, peltiform’.
| 1900 in B. D. Jackson Gloss. Bot. Terms 270/2. |
B. as
n. 1. Short for
thyroid cartilage.
| 1840 E. Wilson Anat. Vade M. (1842) 492 The Thyroid is the largest cartilage of the larynx. 1854 Owen Skel. & Teeth in Orr's Circ. Sc. I. Org. Nat. 210 Extending beyond and sustaining the thyroid and other parts of the larynx. 1868 ― Vertebr. Anim. xxxiii. III. 603 Castration arrests that prominent growth of the thyroid, &c., which accompanies the elongation of the cords. |
2. a. Short for
thyroid gland; also for
thyroid extract or
product (see b).
| 1849–52 Todd's Cycl. Anat. IV. 1102/2 The normal weight of the thyroid is about one ounce. 1897 Allbutt's Syst. Med. IV. 469 The sheep's thyroid is relatively rich in thyro-iodine. Ibid. 476 In cases of..myxœdema the results of treatment by thyroid justify a strong expectation of cure. 1897 Trans. Amer. Pediatric Soc. IX. 65 In cretinism we are certain that the prolonged use of thyroids is followed by distinct changes in the blood. |
b. attrib. thyroid-stimulating a. = thyrotrop(
h)ic adj. s.v. thyro-.
| 1895 Pall Mall G. 16 Dec. 1/3 The use of thyroid extract as a remedy for certain diseases..is looked upon as one of the most brilliant of recent medical discoveries. 1899 Allbutt's Syst. Med. VIII. 68 Thyroid treatment of cases of tetany. Ibid. 673 The horny growth fell off, while the patient was under thyroid feeding. 1941 Trans. Amer. Assoc. Study Goiter 159 Attempts have been made to demonstrate the thyroid stimulating hormone in the urine of patients with thyroid disease. 1974 D. & M. Webster Compar. Vertebr. Morphol. xiii. 307 The thyroid-stimulating hormone, TSH, is produced by basophilic cells [within the pituitary]. |
Hence
thyˈroidal,
thyˈroideal,
thyˈroidean adjs., pertaining to the thyroid cartilage or gland;
thyroiˈdectomize v., trans. to subject to thyroidectomy;
thyroiˈdectomized ppl. a., deprived of the thyroid;
thyroiˈdectomy [
Gr. ἐκτοµή a cutting out], excision of the thyroid gland;
thyˈroidic a. and n., (designating) a person with a disordered thyroid gland;
thyˈroidin, trade-name of a whitish powdered extract of the thyroid gland of the sheep, used as an alterative and an anti-fat;
ˈthyroidism, a morbid state consequent on administration of thyroid extract; thyroid poisoning;
thyroiˈditis, inflammation of the thyroid gland;
thyroidiˈzation, treatment with a preparation of the thyroid (Dorland);
ˈthyroidless a., having no thyroid gland;
thyroiˈdotomy [
Gr. τοµή cutting], incision of the thyroid gland.
| 1860 Mayne Expos. Lex., Thyroideus,..*thyroidal: *thyroidean. 1872 Cohen Dis. Throat 51 The anterior portions of the vocal cords attached to the thyroidal junction. |
| 1827 Abernethy Surg. Wks. II. 127 The superior *thyroideal, lingual, and facial branches of the external carotid. 1854 Jones & Sieveking Pathol. Anat. (1874) 122 Ligature of the thyroideal arteries has caused considerable diminution of a goitrous tumour. |
| 1932 J. S. Huxley Probl. Relative Growth vi. iv. 183 Groups of these [albino rats] were *thyroidectomized. 1974 Nature 5 Apr. 525/1 All rats were ovariectomised and thyroidectomised on day 1 of the experiment. |
| 1899 Allbutt's Syst. Med. VIII. 57 The administration of thyroid in some form to *thyroidectomised animals or man. 1946 Nature 19 Oct. 557/2 Another series of experiments was carried out with thyroidectomized mice. |
| 1889 Buck's Handbk. Med. Sc. VIII. 545/2 Until the middle of the eighteenth century no true *thyroidectomy..had been performed. 1891 Lancet 18 Apr. 907/1 M. Reverdin..has performed thyroidectomy in this disease in fourteen cases. 1897 Allbutt's Syst. Med. III. 314 Thyroid grafts prolong life after complete thyroidectomy. |
| 1922 G. B. Shaw in S. & B. Webb English Local Govt. VI. p. lxiii, By all means let the endocrinists go on dividing abnormal people, in prison and out, into hyper and sub pituitaries and *thyroidics and adrenals. 1965 M. Bradbury Stepping Westward i. 31 This was James Walker, a stout, slightly thyroidic, very shambling person. |
| 1896 Pharmaceutical Jrnl. 5 Sept. 215 *Thyreoidin, the active principle of thyroid. 1897 Allbutt's Syst. Med. III. 315 A non-proteid substance containing a considerable percentage of iodine—the so-called thyroidin. |
| 1897 Ibid. II. 78 In most of them the symptoms of *thyroidism were produced. |
| 1889 Buck's Handbk. Med. Sc. VII. 96/1 Inflammation of the thyroid gland (*thyroiditis..) is most commonly..the..result of remedial measures employed in the treatment of goitre. |
| 1908 *Thyroidless [see anti-thyroid s.v. anti-1 3 b]. 1946 Nature 26 Oct. 590/1 During the third month, mortality was as high as 75 per cent in thyroidless animals, 60 per cent in the controls, and only 15 per cent of the hyperthyroid animals. |
| 1890 Billings Nat. Med. Dict., *Thyroidotomy. |