orbicular, a. (n.)
(ɔːˈbɪkjʊlə(r))
[ad. L. orbiculār-is, f. orbiculus: see orbicle and -ar. Cf. F. orbiculaire (14th c. in Hatz.-Darm.).]
Of the form of a circle or orb; circular, round.
A. adj.
1. a. Round as a circle or disc; circular, or of circular plan or section.
| c 1420 Pallad. on Husb. iii. 230 Vpbounde, orbiculer and turned rounde. 1447 O. Bokenham Seyntys (Roxb.) 182 The hevenys orbiculer revolucyoun From est to west wyth oute cessacyoun. 1596 C. Fitzgeffrey Sir F. Drake (1881) 14 Enclaspeth with her winged eminence The worlds orbicular circumference. c 1611 Chapman Iliad vii. 222 Quite through his bright orbicular targe. 1664 Evelyn Sylva (1776) 504 The trunk or bough of a Tree being cut transversely..sheweth several circles or rings more or less orbicular..one without the other. 1731 Gentl. Mag. I. 238 Signing their Names in an orbicular manner, which they call a round Robin. 1851 D. Wilson Preh. Ann. (1863) I. ii. iv. 399 Shields,..some oblong and oval, and some orbicular. |
b. Anat. and Zool. Applied to various organs or structures of circular, discoidal, or ring-like form; spec. to those muscles (sphincters) surrounding, and having the function of closing, natural apertures of the body, as the sphincters of the mouth, eyelids, iris, anus, bladder, vagina, etc. (Also in L. form orbiculāris.)
orbicular spot (Entom.), a circular spot on the fore-wings of most noctuid moths.
| 1615 Crooke Body of Man 165 The naturall motion, which the Ancients called περισταλτικὸν is accomplished by transuerse and orbicular Fibres contracting the guts. 1691 Ray Creation ii. (1692) 49 The Arteries consist of a quadruple Coat, the Third of which is made up of Annular or Orbicular carneous Fibres. 1761 Sterne Tr. Shandy III. vi, Directing..the o[r]bicular muscles around his lips to do their duty,—he whistled Lillabullero. 1840 G. V. Ellis Anat. 64 The orbicular muscle of the eyelids. 1872 Nicholson Palæont. 212 In Discina, the shell is generally circular or orbicular in shape. |
c. Bot. Applied to leaves, or the like, of circular outline.
| 1753 Chambers Cycl. Suppl. s.v. Leaf, Orbicular Leaf, one of a round figure, the breadth of which is equal to its length. 1785 Martyn Rousseau's Bot. xxiv. (1794) 333 The leaves are almost orbicular. 1835 Lindley Introd. Bot. (1848) II. 354 Orbicular; perfectly circular. 1845 ― Sch. Bot. iv. (1858) 35 Seeds in one row in each cell, oval or orbicular. |
2. Round as a sphere or globe; spherical, globular. Sometimes loosely, Having a rounded or convex (as opp. to a flat) form or surface.
| c 1420 Pallad. on Husb. iii. 891 The meles [= apples] rounde, ycald orbiculer. 1578 Banister Hist. Man i. 33 This same head [of thigh bone] is almost wholly affourmed by an orbicular Appendaunce. 1622 Middleton Honour & Virtue Wks. (Bullen) VII. 367 Here fix my foot on this orbicular ball. 1782 A. Monro Anat. Bones, Nerves, etc. 203 A round head of one bone plays in the orbicular socket of another. 1853 Ruskin Stones Ven. II. viii. §117. 357 Having roses set, instead of orbicular ornaments, between the spandrils. |
3. fig. Full-orbed, rounded, complete.
| 1673 Marvell Reh. Transp. II. 395 The ends of your publick government will at last excuse if not hallow, the most orbicular untruth. 1827–39 De Quincey Murder (1862) 76 The household ruin was thus full and orbicular. 1841 ― Plato's Repub. Wks. 1858 IX. 215 An orbicular system, or total body of philosophy. |
4. Nat. Hist. Combined with other adjs. of form, to express a combination of the two or an intermediate form; (esp. in Bot. of leaves), as orbicular-cordate, orbicular-crenate, orbicular-ovate, etc.
| 1847 W. E. Steele Field Bot. 116 Villarsia Nymphæoides. Leaves orbicular-cordate. 1870 Hooker Stud. Flora 37 Lepidium ruderale..pod orbicular-oblong notched. Ibid. 346 Betula nana..leaves short-petioled orbicular-crenate. Ibid., Alnus glutinosa, L.; leaves..orbicular-cuneate. |
5. orbicular bone (os orbiculare), a very small bone of the middle ear, at the end of the process of the incus (with which it is united in the adult), and articulating with the stapes.
| 1706 Phillips, Orbicular Bone (in Anat.), one of the little Bones of the inner part of the Ear, which is fasten'd by a slender Ligament to the sides of that called Stapes. 1892 Syd. Soc. Lex., Orbicular bone, a very minute bone of the middle ear, like to a grain of sand..; it is a separate bone in childhood, but by some is looked upon as an epiphysis of the incus. |
6. Petrol. Containing orbicules.
| 1824 H. T. De la Beche tr. Sel. Geol. Mem. in Annales des Mines p. ix. Diabase... Orbicular D. Spheres with concentric zones of hornblende and compact felspar in a diabase of moderately sized grains. (Orbicular granite of Corsica.) 1857 J. B. Jukes Student's Man. Geol. iii. 73 (heading) Globular diorite, orbicular greenstone, Corsican granite. 1873 Proc. Geol. Assoc. II. 267 The so-called ‘orbicular silica’. 1954 H. Williams et al. Petrogr. vii. 132 A few granites have an orbicular texture. 1970 K. C. Jackson Textbk. Lithology v. 280 Orbicular granite... Very commonly, the orbicules show abnormal concentration of the ferromagnesium minerals. |
B. n.
† 1. ? Orbicular course, orbit (or ? Orb, sphere).
| 1523 Skelton Garl. Laurel 4 When Mars retrogradant reuersyd his bak, Lorde of the yere in his orbicular. |
2. Anat. An orbicular muscle: see A. 1 b. Also in L. form orbiculāris.
| 1872 Darwin Emotions vi. 149 For the sake of brevity these muscles will generally be spoken of as the orbiculars. 1899 Allbutt's Syst. Med. VIII. 39 Where the orbicularis is thus affected the earliest manifestations may..resemble that quivering of muscles [in the eyelid or other facial muscle] popularly spoken of as ‘live blood’. |
3. Entom. Short for orbicular spot: see A. 1 b.