1. (noun)sphere, domain, area, orbit, field, arena a particularenvironment or walk of life "his social sphere is limited"; "it was a closed area of employment"; "he's out of my orbit"
3. (noun)sphere, sphere of influence the geographical area in which one nation is very influential
4. (noun)sector, sphere a particularaspect of life or activity "he was helpless in an important sector of his life"
5. (noun)sphere a solidfigure bounded by a spherical surface (including the space it encloses)
6. (noun)sphere a three-dimensional closed surface such that every point on the surface is equidistant from the center
7. (noun)celestial sphere, sphere, empyrean, firmament, heavens, vault of heaven, welkin the apparent surface of the imaginarysphere on which celestial bodies appear to be projected