sector in WordNet English dictionary

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