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

Etymology

Origin of sector

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

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

As investors question the value of heavy artificial-intelligence spending, the specter of vendor financing once again hangs over the technology sector.

From MarketWatch ● Jul. 27, 2026

Kuwait Petroleum Corp., the state-owned firm overseeing the sector, and its subsidiary Kuwait Oil Co., which explores and produces oil on behalf of the state, both signed the deal.

From The Wall Street Journal ● Jul. 27, 2026

"Meanwhile, it will boost the company's global influence and help lift its market share in the worldwide memory chip sector."

From Barron's ● Jul. 27, 2026

Any consolidation of the Singapore telecommunications sector could also boost StarHub’s annual revenue per user, he says.

From The Wall Street Journal ● Jul. 27, 2026

Nyla and Crick escort me toward an open pod near the decontamination sector.

From "The Last Cuentista" by Donna Barba Higuera

But he also sees the breakdown as creating some opportunities, as it leads to “a more defensive rotation” into sectors showing some technically bullish tendencies.

From MarketWatch ● Jul. 26, 2026

Most large companies are expected to continue with quarterly reporting while some companies won’t, leading to differences within individual sectors.

From The Wall Street Journal ● Jul. 26, 2026

This week it expanded its Trusted Employer Scheme that fast-tracks worker visas for companies that meet requirements including predominantly employing South Africans, investing in skills development and operating in priority sectors.

From Barron's ● Jul. 26, 2026

The students' protest has resonated with a large section of middle-class India, cutting across identities of religion, caste or sectors, with people voicing anger about the lack of educational opportunities and jobs in India.

From BBC ● Jul. 25, 2026

Then I glide silently from high-rise to high- rise until I’m well out of the Batalla and Ruby sectors.

From "Legend" by Marie Lu

Related Words

• district
• part
• region
• zone