A sphere is a perfectly round geometrical object in three-dimensional space. Like a circle, its two-dimensional analog, a sphere is defined mathematically as the set of points that are all the same distance r from a given point in three-dimensional space. This distance r is the radius of the sphere, and the given point is the center of the sphere. The maximum straight distance through the sphere passes through the centre and is thus twice the radius; it is the diameter.

The above text is a snippet from Wikipedia: Sphere
and as such is available under the Creative Commons Attribution/Share-Alike License.



  1. A regular three-dimensional object in which every cross-section is a circle; the figure described by the revolution of a circle about its diameter .
  2. A spherical physical object; a globe or ball.
  3. The apparent outer limit of space; the edge of the heavens, imagined as a hollow globe within which celestial bodies appear to be embedded.
  4. Any of the concentric hollow transparent globes formerly believed to rotate around the Earth, and which carried the heavenly bodies; there were originally believed to be eight, and later nine and ten; friction between them was thought to cause a harmonious sound (the music of the spheres).
  5. An area of activity for a planet; or by extension, an area of influence for a god, hero etc.
  6. The region in which something or someone is active; one's province, domain.
  7. The set of all points in three-dimensional Euclidean space (or -dimensional space, in topology) that are a fixed distance from a fixed point .
  8. The extension of a general conception, or the totality of the individuals or species to which it may be applied.


  1. To place in a sphere, or among the spheres; to ensphere.
  2. To make round or spherical; to perfect.

The above text is a snippet from Wiktionary: sphere
and as such is available under the Creative Commons Attribution/Share-Alike License.

Need help with a clue?
Try your search in the crossword dictionary!