English Reference
noun

sector

n.
US /ˈsɛktɝ/ UK /sˈɛktɐ/ sec·tor UK spelling sector's, sector's

  1. 01 B2 Upper Intermediate

    a particular area of land or space that is controlled by a certain group.

    a designated area or zone, especially one used for military or administrative purposes.

    Simple

    The city was divided into four sectors, each managed by a different team.

    In context

    The peacekeeping forces were assigned to the northern sector to monitor the border and prevent further escalations of the conflict.

  2. 02 C1 Advanced Technical Math

    a part of a circle that looks like a slice of pie.

    the portion of a circle enclosed by two radii and an arc.

    Simple

    The teacher asked us to calculate the area of the shaded sector.

    In context

    To determine the total area of the circular garden, we must first calculate the dimensions of each individual sector defined by the walking paths.

  3. 03 C1 Advanced Technical Computing

    a small section on a computer hard drive where data is stored.

    a subdivision of a track on a magnetic disk or optical disc.

    Simple

    The computer could not read the file because of a bad sector on the disk.

    In context

    The recovery software attempted to bypass the damaged sectors to retrieve the remaining data from the corrupted hard drive.

  4. 04 C1 Advanced Technical Aviation

    one part of a flight journey, from one airport to the next.

    a single leg of a flight involving one take-off and one landing.

    Simple

    The pilot flew three sectors today before finishing her shift.

    In context

    The airline's scheduling software ensures that crew members do not exceed their maximum duty hours across multiple short-haul sectors.

Usage sector agriculture · sector manufacturing · sector our auto

About two-thirds of the projects are in Scotland, to support the fast-growing wind energy sector.

BBC News· 12 Aug 2026

The government says that it, and the private sector have a responsibility to retrain workers, and risks falling behind competitors like India and Singapore.

BBC News· 4 Aug 2026

Borrowed from Latin sector.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Latin sector
Level B2 · Upper Intermediate
Frequency Common
Updated