noun

• (mathematics) A surface in three dimensions consisting of all points equidistant from a center. .
• (astronomy, now rare) The celestial sphere: the edge of the heavens, imagined as a hollow globe within which celestial bodies appear to be embedded.
  "Though cold and darkness longer hang somewhere, / Yet Phoebus equally lights all the Sphere."
• (historical, astronomy, mythology) 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).
  "ſooner ſhall the Sun fall from his Spheare, Than Tamburlaine be ſlaine or ouercome."
• (mythology) An area of activity for a planet; or by extension, an area of influence for a god, hero etc.

verb

• (transitive) To place in a sphere, or among the spheres; to ensphere.
  "The glorious planet Sol / In noble eminence enthroned and sphered / Amidst the other."
• (transitive) To make round or spherical; to perfect.
  "sphered Whole"