sector

sector — noun

1. one of the parts that a country's economy is divided into, such as industry, far

1.nounB1
Definition

one of the parts that a country's economy is divided into, such as industry, farming, banking, or healthcare

Example

The technology sector has created thousands of new jobs across Taiwan this year.

collocation: technology sector / manufacturing sector / service sector

Mizuki's research focuses on the renewable energy sector in Southeast Asia.

determiner + sector + preposition: sector in [region]

Common collocations
  • private sector
  • public sector
  • financial sector
  • service sector
  • manufacturing sector
  • technology sector
  • agricultural sector
Synonyms
  • industry

    narrower — usually refers to a specific type of business activity (e.g. the car industry), while sector is broader

  • field

    less formal and can also mean a subject or profession rather than an economic division

  • branch

    emphasises a subdivision within a larger organisation or system

Grammar Patterns

the + ~

~ + noun

Common Mistakes

I work in a sector of education.
I work in the education sector.
'sector' is normally used with a determiner that specifies which economic field, not introduced as 'a sector of + field'.

2. a stretch of territory, water, or sky that has been marked off from neighbouring

2.nounB1
Definition

a stretch of territory, water, or sky that has been marked off from neighbouring zones and placed under the authority of a specific country, military unit, or organisation

Example

The army secured the northern sector of the city before dawn.

adjective + sector: northern/southern/eastern/western sector

Soraya's unit was responsible for patrolling the coastal sector south of the port.

Common collocations
  • northern sector
  • southern sector
  • eastern sector
  • western sector
  • military sector
  • coastal sector
  • demilitarised sector
Synonyms
  • zone

    broader — can be used for any defined area, not necessarily under military control

  • region

    larger and less strictly demarcated; implies a natural rather than imposed division

  • district

    usually an administrative or residential division within a city or country

Grammar Patterns

the + adjective + ~

~ + of + place

Usage Note

Frequently used with a directional adjective (northern, southern, eastern, western) to specify which part of a larger region is meant. 'Sector' in this sense implies deliberate division, not a natural area.

Common Mistakes

The sector of the forest is very beautiful.
The northern sector of the forest is very beautiful.
without a directional or controlling modifier, the geographic sense sounds vague.

3. a wedge-shaped portion of a flat circle, bounded on two sides by lines from the

3.nounB2
Definition

a wedge-shaped portion of a flat circle, bounded on two sides by lines from the centre point to the edge and on the third side by the arc of the outer curve

Example

The student shaded the sector that lies between the two radii.

passive: the sector [that lies / is bounded] between...

Ezra calculated the area of a 60-degree sector for his geometry homework.

measurement: [number]-degree sector

Common collocations
  • circular sector
  • sector of a circle
  • angle of a sector
  • area of a sector
  • degree sector
Synonyms
  • segment

    different shape — bounded by a chord (straight line across the circle) rather than two radii

  • slice

    everyday word for the same shape; less formal and not used in mathematical writing

Grammar Patterns

the ~ of a circle

~ + of + number + degrees

Usage Note

This is a technical term in geometry. Outside mathematics, people usually say 'slice' or 'section' instead. Extended to pie charts and similar circular diagrams.

Common Mistakes

A sector is any part of a circle.
A sector is a part of a circle bounded by two radii and the arc between them.
any part of a circle could be a segment (bounded by a chord), not a sector.

4. a small storage unit on a rotating device such as a hard drive or CD, where a fi

4.nounB2
Definition

a small storage unit on a rotating device such as a hard drive or CD, where a fixed amount of data can be written and read as one block

Example

The hard drive's read head failed when it tried to access sector 512.

verb + sector: access / read / write a sector

Niran used a disk utility to scan for and repair the damaged sectors.

Common collocations
  • bad sector
  • disk sector
  • sector size
  • sector number
  • damaged sector
  • boot sector
Synonyms
  • block

    often used interchangeably but technically refers to the operating system's unit, while sector is the hardware-level unit

  • cluster

    a group of sectors treated as one unit by the file system

Grammar Patterns

~ + number

bad + ~

~ + on + disk

Usage Note

Usually passive when describing recovery ('sectors are read'). Each sector on a typical disk stores 512 or 4096 bytes. 'Bad sector' is the most common collocation for non-technical users.

Common Mistakes

My file is saved in sector 45.
My file is stored across several sectors on the disk.
a single file typically occupies multiple sectors; users do not normally choose which sector to use.

sector — verb

Word family

Synonym discussion

Sense: noun/1

Sector, industry, field, and branch all refer to divisions of activity, but they differ in scope and typical use. Sector is the broadest term, used for large divisions of a country's economy (the public sector, the service sector). Industry is narrower and refers to businesses that produce a specific type of goods or services (the car industry, the film industry). Field is more general and can cover any subject of work or study (the field of medicine, the field of education — note: 'sector of education' sounds unnatural). Branch emphasises a subdivision within a larger organisation or system (a branch of the military, a branch of mathematics). Choose sector when discussing economic policy or large-scale divisions; choose industry for specific business types; choose field for academic or professional domains; choose branch for organisational sub-parts.

sector ↗industry ↗field ↗branch ↗

Common collocations

Nouns

  • sector growth
  • sector performance
  • sector analysis
  • sector boundaries
  • sector reform

Adverbs

Phrases

  • public and private sectors
  • sector by sector
  • across all sectors of the economy

Prepositions

  • in a sector
  • across sectors
  • into sectors
  • by sector

Etymology

LatinEnglish

Sector comes directly from the Latin word 'sector', meaning 'one who cuts' or 'a cutter', derived from 'secare' (to cut). The mathematical sense — a part of a circle cut by two radii — was the first meaning in English (16th century). The military and economic meanings developed later, based on the idea of something being cut or divided into separate areas.