orbit

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The path of a celestial body or an artificial satellite as it revolves around another body.
2. n. One complete revolution of such a body.
3. n. The path of a body in a field of force surrounding another body; for example, the movement of an atomic electron in relation to a nucleus.
4. n. A range of activity, experience, or knowledge.
5. n. A range of control or influence: "What magnetism drew these quaking ruined creatures into his orbit?” ( Malcolm Lowry). See Synonyms at range.
6. n. Either of two bony cavities in the skull containing an eye and its external structures; an eye socket.
7. v. To put into an orbit: orbit a satellite.
8. v. To revolve around (a center of attraction): The moon orbits Earth.
9. v. To move in an orbit.

Century Dictionary and Cyclopedia

1. n. Track; course; path, especially a path, as that in a circle or an ellipse, which returns into itself; specifically, in astronomy, the path of a planet or comet; the curve-line which a planet describes in its periodical revolution round its central body or center of revolution: as, the orbit of Jupiter or Mercury. The orbits of the planets are elliptical, having the sun in one of the foci; and they all move in these ellipses by this law—that a straight line drawn from the center of the sun to the center of any one of them, termed the radius vector, always describes equal areas in equal times. Also, the squares of the times of the planetary revolutions are as the cubes of their mean distances from the sun. These are called Kepler's laws (see law). The attractions of the planets for one another slightly derange these laws, and cause the orbits to undergo various changes. The satellites, too, move in elliptical orbits, having their respective primaries in one of the foci. The parabolic and hyperbolic paths of comets are also called orbits. The elements of an orbit are those quantities by which its position and magnitude for the time are determined, such as the major axis and eccentricity, the longitude of the node and the inclination of the plane to the ecliptic, and the longitude of the perihelion. In the ancient astronomy the orbit of a planet is its eccentric or the deferent of its epicycle.
2. n. A small orb, globe, or ball.
3. n. In anatomy and zoology, the bony cavity of the skull which contains the eye; the eye-socket. In man the orbits are a pair of quadrilateral pyramidal cavities completely surrounded by bone, and separated from though communicating with the cranial cavity and the nasal and temporal fossæ, and opening forward upon the face, with the apex at the optic foramen where the optic nerve enters. Seven bones enter into the formation of each orbit, the frontal, sphenoid, ethmoid, maxillary, palatal, lacrymal, and malar, of which the first-named three are common to both orbits. Each orbit communicates with surrounding cavities by several openings, the principal of which are—with the cranial cavity by the optic foramen and sphenoidal fissure; with the nasal fossæ by the lacrymal canal; with the temporal and zygomatic fossæ by the sphenomaxillary fissure; with ethmoidal parts by the anterior and posterior ethmoidal foramina; and with the face by supra-orbital, infra-orbital, extra-orbital, and malar foramina. The orbit contains the eye and its associate muscular, vascular, glandular, sustentacular, mucous, and nervous structures.
4. n. In ornithology, the orbita, or circumorbital region of a bird's head; the skin of the eyelids and adjoining parts.
5. n. In entomology, the border surrounding the compound eye of an insect, especially when it forms a raised ring, or differs in color or texture from the rest of the head. In Diptera the different parts of this border are distinguished as the anterior or facial orbit, the inferior or genal, the posterior or occipital, the superior or vertical, and the frontal, according to the regions of the head of which they form a part. When not otherwise stated, orbit generally means the inner margin of the eye, or that formed by the epicranium.

Wiktionary

1. n. A circular or elliptical path of one object around another object.
2. n. A sphere of influence; an area of control.
3. n. The course of one's usual progression, or the extent of one's typical range.
4. n. anatomy The bony cavity containing the eyeball; the eye socket.
5. n. physics The path an electron takes around an atom's nucleus.
6. n. mathematics A collection of points related by the evolution function of a dynamical system.
7. v. To circle or revolve around another object.
8. v. To move around the general vicinity of something.
9. v. To place an object into an orbit around a planet.

GNU Webster's 1913

1. n. (Astron.) The path described by a heavenly body in its periodical revolution around another body.
2. n. Rare & Improper An orb or ball.
3. n. (Anat.) The cavity or socket of the skull in which the eye and its appendages are situated.
4. n. (Zoöl.) The skin which surrounds the eye of a bird.

WordNet 3.0

1. v. move in an orbit
2. n. a particular environment or walk of life
3. n. the (usually elliptical) path described by one celestial body in its revolution about another
4. n. the bony cavity in the skull containing the eyeball
5. n. an area in which something acts or operates or has power or control:
6. n. the path of an electron around the nucleus of an atom