Main Entry: ¹sphere

Pronunciation: \ˈsfir\

Function: noun

Etymology: Middle English spere globe, celestial sphere, from Anglo-French espere, from Latin sphaera, from Greek sphaira, literally, ball; perhaps akin to Greek spairein to quiver — more at spurn

Date: 14th century

1 a (1) : the apparent surface of the heavens of which half forms the dome of the visible sky (2) : any of the concentric and eccentric revolving spherical transparent shells in which according to ancient astronomy stars, sun, planets, and moon are set b : a globe depicting such a sphere; broadly : globe a
2 a : a globular body : ball b : planet, star c (1) : a solid that is bounded by a surface consisting of all points at a given distance from a point constituting its center — see volume table (2) : the bounding surface of a sphere
3 : natural, normal, or proper place; especially : social order or rank <not in the same sphere as his moneyed friends>
4 a obsolete : orbit b : an area or range over or within which someone or something acts, exists, or has influence or significance <the public sphere>

— spher·ic \ˈsfir-ik, ˈsfer-\ adjective, archaic

— sphe·ric·i·ty \sfir-ˈi-sə-tē\ noun