Chapter Orangery to Orchidology of O by Webster's Dictionary (1913 Edition)

Orbicular
(Or*bic"u*lar) a. [L. orbicularis, fr. orbiculus, dim. of orbis orb: cf. F. orbiculaire.] Resembling or having the form of an orb; spherical; circular; orbiculate. — Or*bic"u*lar*ly, adv. — Or*bic"u*lar*ness, n.

Orbicular as the disk of a planet.

De Quincey.

Orbiculate
(Or*bic"u*late) n. That which is orbiculate; especially, a solid the vertical section of which is oval, and the horizontal section circular.

Orbiculate
(Or*bic"u*late Or*bic"u*la`ted) a. [L. orbiculatus. See Orbicular.] Made, or being, in the form of an orb; having a circular, or nearly circular, or a spheroidal, outline.

Orbiculate leaf (Bot.), a leaf whose outline is nearly circular.

Orbiculation
(Or*bic`u*la"tion) n. The state or quality of being orbiculate; orbicularness. Dr. H. More.

Orbit
(Or"bit) n. [L. orbita a track or rut made by a wheel, course, circuit, fr. orbis a circle: cf. F. orbite. See 2d Orb.]

1. (Astron.) The path described by a heavenly body in its periodical revolution around another body; as, the orbit of Jupiter, of the earth, of the moon.

2. An orb or ball. [Rare & Improper]

Roll the lucid orbit of an eye.

Young.

3. (Anat.) The cavity or socket of the skull in which the eye and its appendages are situated.

4. (Zoöl.) The skin which surrounds the eye of a bird.

Orbital
(Or"bit*al) a. Of or pertaining to an orbit. "Orbital revolution." J. D. Forbes.

Orbital index (Anat.), in the skull, the ratio of the vertical height to the transverse width of the orbit, which is taken as the standard, equal to 100.

Orbitar
(Or"bit*ar) a. [Cf. F. orbitaire.] Orbital. [R.] Dunglison.

Orbitary
(Or"bit*a*ry) a. Situated around the orbit; as, the orbitary feathers of a bird.

Orbitelæ
(||Or`bi*te"læ) n. pl. [NL., fr. L. orbis an orb + tela a web.] (Zoöl.) A division of spiders, including those that make geometrical webs, as the garden spider, or Epeira.

Orbitolites
(||Or`bi*to*li"tes) n. [NL. See Orbit, and -lite.] (Zoöl.) A genus of living Foraminifera, forming broad, thin, circular disks, containing numerous small chambers.

Orbitonasal
(Or`bi*to*na"sal) a. [Orbit + nasal.] (Anat.) Of or pertaining to the orbit and the nose; as, the orbitonasal, or ophthalmic, nerve.

Orbitosphenoid
(Or`bi*to*sphe"noid) a. [Orbit + sphenoid.] (Anat.) Of or pertaining to the sphenoid bone and the orbit, or to the orbitosphenoid bone. — n. The orbitosphenoid bone, which is situated in the orbit on either side of the presphenoid. It generally forms a part of the sphenoid in the adult.

Orbitosphenoidal
(Or`bi*to*sphe*noid"al) a. (Anat.) Of or pertaining to the orbitosphenoid bone; orbitosphenoid.

Orbituary
(Or*bit"u*a*ry) a. Orbital. [R.]