sphere sphere /sˈfɪr/

noun

1. () Any spherically shaped artifact  ( sphere )
   any spherically shaped artifact
     The crystal ball resembled a perfectly spherical shape.
   The crystal ball resembled a perfectly spherical shape.
   
   
2. () A particular environment or walk of life  ( arena , orbit , domain , area , field , sphere )
   a particular environment or walk of life
    His social sphere is limited
   his social sphere is limited
    It was a closed area of employment
   it was a closed area of employment
    He's out of my orbit
   he's out of my orbit
   
3. () A particular aspect of life or activity  ( sphere , sector )
   a particular aspect of life or activity
    He was helpless in an important sector of his life
   he was helpless in an important sector of his life
   
4. () The geographical area in which one nation is very influential  ( sphere of influence , sphere )
   the geographical area in which one nation is very influential
   
5. The apparent surface of the imaginary sphere on which celestial bodies appear to be projected  ( celestial sphere , empyrean , firmament , heavens , sphere , vault of heaven , welkin )
   the apparent surface of the imaginary sphere on which celestial bodies appear to be projected
    On a clear night, one can gaze at the heavens and see countless stars.
   On a clear night, one can gaze at the heavens and see countless stars.
   
   
6. A three-dimensional closed surface such that every point on the surface is equidistant from the center  ( sphere )
   a three-dimensional closed surface such that every point on the surface is equidistant from the center
    The earth is a sphere
   The earth is a sphere
   
   
7. A solid figure bounded by a spherical surface (including the space it encloses)  ( sphere )
   a solid figure bounded by a spherical surface (including the space it encloses)
    The artist created a sculpture incorporating a large metal sphere at its center.
   The artist created a sculpture incorporating a large metal sphere at its center.