sector

noun

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