sphere

The apparent surface of the imaginary sphere on which celestial bodies appear to be projected.

A particular aspect of life or activity.

A particular environment or walk of life.

“his social sphere is limited”

The geographical area in which one nation is very influential.

Any spherically shaped artifact.

A solid figure bounded by a spherical surface (including the space it encloses).

A three-dimensional closed surface such that every point on the surface is equidistant from the center.