sec·tor (sĕktər, -tôr′)
1. A part or division, as of a city or a national economy: the manufacturing sector.
a. The portion of a circle bounded by two radii and the included arc.
b. A measuring instrument consisting of two graduated arms hinged together at one end.
3. Computers A portion of a storage device making up the smallest addressable unit of information.
a. A division of a defensive position for which one military unit is responsible.
b. A division of an offensive military position.
tr.v. sec·tored, sec·tor·ing, sec·tors
To divide (something) into sectors.
[Late Latin, from Latin, cutter, from sectus, past participle of secāre, to cut; see sek- in the Appendix of Indo-European roots.]
sec·tori·al (-tôrē-əl) adj.
(click for a larger image)sector
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.