sector
Americannoun
-
Geometry. a plane figure bounded by two radii and the included arc of a circle.
-
a distinct part, especially of society or of a nation's economy.
the housing sector; the educational sector.
-
a section or zone, as of a city.
-
Military. a designated defense area, usually in a combat zone, within which a particular military unit operates and for which it is responsible.
-
a mathematical instrument consisting of two flat rulers hinged together at one end and bearing various scales.
-
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.
-
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.
-
Computers. a portion of a larger block of storage, as 1/128 of a track or disk.
verb (used with object)
noun
-
a part or subdivision, esp of a society or an economy
the private sector
-
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)
-
a measuring instrument consisting of two graduated arms hinged at one end
-
a part or subdivision of an area of military operations
-
computing the smallest addressable portion of the track on a magnetic tape, disk, or drum store
Other Word Forms
Derived Forms
Inflected Forms
Nouns
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."
Vocabulary lists containing sector
Unit 3: Compelling Evidence
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
"The Fun They Had"
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
Geometry - High School
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
Dubai will offer more than $800 worth of discounts and deals to residents who bring friends and family to visit, the emirate's media office said, as months of war have battered its tourism sector.
From Barron's ● Jul. 22, 2026
Find insight on Yangzijiang Shipbuilding, GM and more in the latest Market Talks covering the auto and transport sector.
From The Wall Street Journal ● Jul. 22, 2026
A familiar inquiry after his recent notes has been “What is your favorite sector here?”
From MarketWatch ● Jul. 22, 2026
The spending is part of a larger race across the tech sector to stay competitive amid soaring demand for computing power.
From Barron's ● Jul. 22, 2026
The Germans suffered equally, but they quickly rebuilt their defensive positions, and the Arras sector returned to the stalemate still gripping the Western Front.
From "The War to End All Wars: World War I" by Russell Freedman
That’s what expanding breadth looks like, as a bull market supported by several sectors is much sturdier than one balanced on a tower of parabolic semiconductor stocks.
From MarketWatch ● Jul. 22, 2026
The Welsh government welcomed the report and said "improving the health of the Cleddau requires action across all sectors".
From BBC ● Jul. 22, 2026
A bull market supported by several sectors is much sturdier than one balanced on a tower of parabolic semiconductor stocks.
From MarketWatch ● Jul. 22, 2026
Hong Kong has been one of the world’s busiest places for listings this year, fueled by a fundraising frenzy largely driven by Chinese companies associated with the artificial-intelligence, biotechnology, and pharmaceutical sectors.
From The Wall Street Journal ● Jul. 21, 2026
They understood now that if anyone had been locked away in other sectors of the citadel they would have died within days.
From "Strange the Dreamer" by Laini Taylor
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.