sector

American  

[sek-ter] / ˈsɛk tər /

noun

• sectors
  plural

1. Geometry. a plane figure bounded by two radii and the included arc of a circle.

2. a distinct part, especially of society or of a nation's economy.

   the housing sector; the educational sector.

3. a section or zone, as of a city.

4. Military. a designated defense area, usually in a combat zone, within which a particular military unit operates and for which it is responsible.

5. a mathematical instrument consisting of two flat rulers hinged together at one end and bearing various scales.

6. Machinery. a device used in connection with an index plate, consisting of two arms rotating about the center of the plate and set to indicate the angle through which the work is indexed.

7. Astronomy. an instrument shaped like a sector of a circle, having a variable central angle and sights along the two straight sides, for measuring the angular distance between two celestial bodies.

8. Computers. a portion of a larger block of storage, as 1/128 of a track or disk.

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verb (used with object)

1. to divide into sectors.

sector British  

/ ˈsɛktə /

noun

1. a part or subdivision, esp of a society or an economy

   the private sector

2. geometry either portion of a circle included between two radii and an arc. Area: 1/ 2 r ²θ, where r is the radius and θ is the central angle subtended by the arc (in radians)

3. a measuring instrument consisting of two graduated arms hinged at one end

4. a part or subdivision of an area of military operations

5. computing the smallest addressable portion of the track on a magnetic tape, disk, or drum store

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sector Scientific  

/ sĕk′tər /

1. The part of a circle bounded by two radii and the arc between them.

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Other Word Forms

Derived Forms

• subsector
  noun
• sectoral
  adjective

Inflected Forms

Nouns

• sectors
  plural

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Etymology

Origin of sector

First recorded in 1560–70; from Late Latin, from Latin: “cutter,” from sec(āre) “to cut, divide” + -tor -tor

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Explanation

Sector sounds like section, doesn't it? That's a good way to remember that a sector is a specific part of society or the economy, made up of similar elements — like the health care sector or the education sector. Our most common use of the word sector refers to a society’s divisions. For example, our economy is divided into the private sector (privately-owned interests) and the public sector (government). Other than that, the word also has many technical applications in math and science. From the Latin verb secare, "to cut," sector was applied long ago to math as a section of a circle, which carried through to military language as "a circle around a headquarters."

Example Sentences

See Examples For:

sector sectors

Despite the new code of ethics, there is no uniform approach across Scotland's museum sector with different institutions given leeway on how to implement it.

From BBC ● Oct. 23, 2026

Find insight on Volvo Car, Tesla and more in the latest Market Talks covering the auto and transport sector.

From The Wall Street Journal ● Oct. 23, 2026

One person familiar with the deliberations said that U.S. officials had considered backing an idea for publicly held American oil companies like Chevron, Exxon and Conoco to carve up and rehabilitate Venezuela’s aging oil sector.

From Salon ● Oct. 23, 2026

Fiercely proud of its culinary traditions, India is increasingly open to foreign influences, with French cooking schools attracting students eager to make their mark on the country's growing fine-dining sector.

From Barron's ● Oct. 23, 2026

Thanks to their complete lack of subtlety, the whole world now knew the Jade Key must be hidden somewhere in that sector.

From "Ready Player One: A Novel" by Ernest Cline

The move requires the chancellor to "flex fiscal rules", according to the paper, with Treasury arguing "it would create and support 100,000 jobs in sectors including AI, defence and green energy by 2035".

From BBC ● Oct. 23, 2026

Stocks in sectors that are sensitive to economic shifts, including banks and industrial firms, were among those leading losses in the S&P 500.

From The Wall Street Journal ● Oct. 23, 2026

Hema, 49, from Surrey, is an HR and talent professional who has worked internationally across multiple sectors.

From BBC ● Oct. 22, 2026

And those experts see precisely those sectors as enjoying "high growth between now and 2030."

From Barron's ● Oct. 21, 2026

From here I can see all of downtown Los Angeles, as well as many of its surrounding sectors, and the thin rim of land that separates the enormous lake from the Pacific Ocean.

From "Legend" by Marie Lu

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Related Words

• district
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