sector Meaning, Definition & Usage

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

WordNet

Sec"tor noun
Etymology
L., properly, a cutter, fr. secare, sectum, to cut: cf. F. secteur. See Section.
Definitions
  1. (Geom.) A part of a circle comprehended between two radii and the included arc.
  2. A mathematical instrument, consisting of two rulers connected at one end by a joint, each arm marked with several scales, as of equal parts, chords, sines, tangents, etc., one scale of each kind on each arm, and all on lines radiating from the common center of motion. The sector is used for plotting, etc., to any scale.
  3. An astronomical instrument, the limb of which embraces a small portion only of a circle, used for measuring differences of declination too great for the compass of a micrometer. When it is used for measuring zenith distances of stars, it is called a zenith sector.

Webster 1913