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

RHB maintains an overweight rating on the Malaysian plantation sector.

From The Wall Street Journal ● Jul. 27, 2026

The performance of the group, whose brands include Louis Vuitton, Dior, Celine and Hennessy, could be a sign that the struggling luxury sector is starting to turn the corner.

From Barron's ● Jul. 27, 2026

The companies that manage Kuwait’s oil sector signed a $16 billion lease agreement with a group of investors led by Blackstone, Brookfield and KKR KKR 3.53%increase; up pointing triangle .

From The Wall Street Journal ● Jul. 27, 2026

What was in dispute was how much money the prisons would receive and how much would go to the civilian sector.

From "Mountains Beyond Mountains" by Tracy Kidder and Michael French

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

Here is a look at how the 11 sectors of the S&P 500 have performed this year, excluding dividends, through Thursday.

From MarketWatch ● Jul. 24, 2026

The British Chambers of Commerce trade expert William Bain points to the competitive advantage for EU exporters into the US in some sectors.

From BBC ● Jul. 24, 2026

Volunteers are trained for about three months before they are sent overseas for twenty-four months of service in several sectors.

From "At Last She Stood" by Erin Entrada Kelly

Related Words

• district
• part
• region
• zone