- noun an object in the shape of a ball
- A solid figure in which all points on its surface are the same distance from the center. Also, that which resembles a sphere, such as the planet earth, or another celestial body.
- A three-dimensional surface within which all points are same distance from the center.
Origin & History of “sphere”
Sphere goes back ultimately to Greek sphaira, a word of uncertain origin, which reached English via Latin sphaera or sphēra and Old French espere. Amongst the theories put forward to account for its ancestry are that it was derived from Greek sphurás ‘fall of dung, round pellet of dung, pill’, which has relatives in Lithuanian spira ‘sheep-dung’ and modern Icelandic sperthill ‘goat-dung’; and that it is related to Greek spaírein ‘quiver’ and Sanskrit sphur- ‘spring, quiver, trouble’. It metaphorical use in English for ‘area of activity’ dates from the early 17th century.