sphere

a particular environment or walk of life; "his social sphere is limited"; "it was a closed area of employment"; "he's out of my orbit"

any spherically shaped artifact

the geographical area in which one nation is very influential

a particular aspect of life or activity; "he was helpless in an important sector of his life"

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

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