discoidadj.n.
/ˈdɪskɔɪd/, U.S. /ˈdɪˌskɔɪd/ A. adj.
1. Botany. Of a composite flower: composed only of disc florets, with no ray florets, as in tansy. Cf. disc n. 7a.
ΘΚΠ
the world > plants > particular plants > plants and herbs > according to family > Compositae (composite plants) > [adjective] > of parts of composite plants
radiated1665
radiate1668
discoidal1706
discoid1712
disciform1830
obligulate1857
1712 J. Morton Nat. Hist. Northants. vi. 369 (heading) Of the Fifth Class, containing the Herbs with a compounded Discoid Flower, that is, a Flower composed of many tubulous little Flowers.
1785 T. Martyn tr. J.-J. Rousseau Lett. Elements Bot. x. 107 Ray called them Discoid flowers.
1857 A. Henfrey Elem. Course Bot. §131 Some capitula are wholly discoid, such as those of Groundsel, of Thistles, etc.
1870 J. D. Hooker Student's Flora Brit. Islands 184 Flowers all tubular (head discoid).
1951 Bull. Torrey Bot. Club 78 169 The [flower] heads are technically discoid..or sometimes radiatiform.
2012 L. R. Blackwell Wildflowers Calif. 311 Although the flower heads are rayless, this is a very showy plant, as the discoid flower heads can almost completely cover the stems and leaves.
2. gen. Of the form of a disc, disc-shaped; (more or less) flat and circular; (Zoology, of a shell or part of one) having the form of a flat spiral, planispiral.
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the world > space > shape > curvature > roundness > [adjective] > circular > having shape of disc
discous1706
discoid1729
disc-like1787
disc-shaped1801
disciform1807
discoidal1808
discal1839
discose1989
1729 J. Woodward Nat. Hist. Fossils I. 121 The Mycetitæ that are of a Discoid or flat Figure.
1757 T. Shaw Trav. Barbary & Levant (ed. 2) 444 A curious echinus, of the discoide kind.
1812 J. Sowerby Mineral Conchol. Great Brit. I. 125 Vermicularia concava... Discoid, involute, concave on one side; the last whorl but slightly attached.
1830 J. Lindley Introd. Nat. Syst. Bot. 101 Stigmas..discoid and 4-lobed.
1854 C. H. Jones & E. H. Sieveking Man. Pathol. Anat. (1874) 7 The red corpuscles are round discoid bodies, with two concave surfaces.
1909 Bull. U.S. Geol. Surv. No. 404. 11 The flow structure is marked by courses of discoid nodules of mica.
1952 G. F. Hervey & J. Hems Freshwater Trop. Aquarium Fishes 368 The body is deep and so laterally compressed that it is discoid.
2004 N.Y. Times (Nexis) 27 Jan. f 3/2 A thin, discoid knife made of green jasper.
B. n.
An object having (more or less) the shape of a disc; (Zoology) a planispiral shell (now rare).
ΘΚΠ
the world > space > shape > curvature > roundness > [noun] > circularity > a circle > a disc
round1615
flat1732
disc1780
discoid1828
1828 N. Webster Amer. Dict. Eng. Lang. Discoid, something in form of a discus or disk.
1846 J. E. Worcester Universal Dict. Eng. Lang. Discoid (Conch.), a univalve shell of which the whorls are disposed vertically on the same plane so as to form a disk.
1856 C. Martel Princ. Form Ornamental Art p. x (caption) Discoids, having a breadth of at least five times the height.
1930 H. Shapley Flights from Chaos xii. 128 A supergalactic system is displacing the unified discoid of stars and stellar clouds.
1968 H. O. Mackey & J. P. Mackey Handbk. Dis. Skin (ed. 9) xix. 189 Papular eczema..is characterized by an outbreak of reddish, rounded or acuminate papules frequently forming plaques or discoids.
2007 A. Cremin Archaeologica 73/2 Other items..found at this site include small, thin, partly bifacial knives, discoids, discoidal cores, and faceted platform flakes.
This entry has been updated (OED Third Edition, December 2013; most recently modified version published online March 2022).
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adj.n.1712