sector

(n) a plane figure bounded by two radii and the included arc of a circle
(n) a social group that forms part of the society or the economy
- the public sector
(n) a particular aspect of life or activity
- he was helpless in an important sector of his life
sphere,
(n) the minimum track length that can be assigned to store information; unless otherwise specified a sector of data consists of 512 bytes
(n) a portion of a military position
(n) measuring instrument consisting of two graduated arms hinged at one end

sphere

sectorial