1. A three-dimensional closed surface such that every point on the surface is equidistant from the centre
   "The mathematician described the properties of a perfect sphere"
    
2. A solid figure bounded by a spherical surface (including the space it encloses)
   "The Earth is not exactly a sphere"
    
3. Any spherically shaped artifact
   "The children played with colourful spheres in the playground"
    
4. A particular environment or walk of life
   "his social sphere is limited";
   - domain, area, orbit, field, arena
    
5. A particular aspect of life or activity
   "he was helpless in an important sphere of his life";
   - sector
    
6. The geographical area in which one nation is very influential
   "During the Cold War, Eastern Europe was considered within the Soviet Union's sphere of influence";
   - sphere of influence
    
7. The apparent surface of the imaginary sphere on which celestial bodies appear to be projected
   "Ancient astronomers used the celestial sphere to map star positions";
   - celestial sphere, empyrean, firmament, heavens, vault of heaven, welkin

Derived forms: spheres

Type of: artefact [Brit], artifact [N. Amer], aspect, environment, facet, geographic area, geographic region, geographical area, geographical region, round shape, surface

Encyclopedia: Sphere