sphere

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Mathematics A three-dimensional surface, all points of which are equidistant from a fixed point.
• noun A spherical object or figure.
• noun A celestial body, such as a planet or star.
• noun The sky, appearing as a hemisphere to an observer.
• noun Any of a series of concentric, transparent, revolving globes that together were once thought to contain the moon, sun, planets, and stars.
• noun A range or extent of knowledge, interest, or activity: synonym: field.
• noun A social level or part of society or group.
• noun A range of power or influence.
• transitive verb To form into a sphere.
• transitive verb To put in or within a sphere.

from The Century Dictionary.

• To make into a sphere; make spherical; round, or round out; fill out completely.
• To place in a sphere or among the spheres: ensphere.
• To inclose as in a sphere or orbit; encircle; engirdle.
• To pass or send as in a sphere or orbit; circulate.
• noun A spherical sponge-spicule, a modified form of the monaxial type.
• noun In geometry, a solid figure generated by the revolution of a semicircle about its diameter.
• noun Hence A rounded body, approximately spherical; a ball; a globe.
• noun An orbicular body representing the earth or the apparent heavens, or illustrating their astronomical relations.
• noun Hence The visible supernal region; the upper air; the heavens; the sky.
• noun One of the supposed concentric and eccentric revolving rigid and transparent shells called crystalline, in which, according to the old astronomers (following Eudoxus), the stars, sun, moon, and planets were severally set, and by which they were carried in such a manner as to produce their apparent motions.
• noun Hence An orbicular field or course of movement; an orbit, as that of a heavenly body or of the eye; a circuit.
• noun Place or scene of action; the space within which movement is made or operations are carried on; a circumscribed region of action: as, the sphere of a mission; the spheres (fuller, spheres of influence) of the different European powers and trading companies in Africa.
• noun Position or rank in society; position or class with reference to social distinctions.
• noun Circuit or radius, as of knowledge, influence, or activity; definite or circumscribed range; determinate limit of any mental or physical course: as, the sphere of diplomacy.
• noun More generally, a sphere (discovered in 1884 by the Italian mathematician Intrigila) belonging to any tetrahedron, and passing thruogh the four feet of the perpendiculars from the summits upon the opposite faces, and consequently also through the mid-points of the lines from the summits to the center of the hyperboloid of which these perpendiculars are generator, and through the orthogonal projections of these points upon the opposite faces.
• noun = Syn. 1–3. Orb, Ball, etc. See globe.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Geom.) A body or space contained under a single surface, which in every part is equally distant from a point within called its center.
• noun Hence, any globe or globular body, especially a celestial one, as the sun, a planet, or the earth.
• noun The apparent surface of the heavens, which is assumed to be spherical and everywhere equally distant, in which the heavenly bodies appear to have their places, and on which the various astronomical circles, as of right ascension and declination, the equator, ecliptic, etc., are conceived to be drawn; an ideal geometrical sphere, with the astronomical and geographical circles in their proper positions on it.
• noun In ancient astronomy, one of the concentric and eccentric revolving spherical transparent shells in which the stars, sun, planets, and moon were supposed to be set, and by which they were carried, in such a manner as to produce their apparent motions.
• noun (Logic) The extension of a general conception, or the totality of the individuals or species to which it may be applied.
• noun Circuit or range of action, knowledge, or influence; compass; province; employment; place of existence.
• noun Rank; order of society; social positions.
• noun rare An orbit, as of a star; a socket.
• noun See under Armillary, Crystalline,.
• noun applications of the principles of spherical trigonometry to the properties and relations of the circles of the sphere, and the problems connected with them, in astronomy and geography, as to the latitudes and longitudes, distance and bearing, of places on the earth, and the right ascension and declination, altitude and azimuth, rising and setting, etc., of the heavenly bodies; spherical geometry.
• noun See under Music.
• transitive verb To place in a sphere, or among the spheres; to insphere.
• transitive verb To form into roundness; to make spherical, or spheral; to perfect.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• verb transitive To place in a sphere, or among the spheres; to ensphere.
• verb transitive To make round or spherical; to perfect.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the geographical area in which one nation is very influential
• noun any spherically shaped artifact
• noun a solid figure bounded by a spherical surface (including the space it encloses)
• noun a three-dimensional closed surface such that every point on the surface is equidistant from the center
• noun a particular environment or walk of life