peripheral

American  

[puh-rif-er-uhl] / pəˈrɪf ər əl /

adjective

1. relating to, situated in, or constituting the periphery.

   peripheral resistance on the outskirts of the battle area.

2. concerned with relatively minor, irrelevant, or superficial aspects of the subject in question.

3. Anatomy. near the surface or outside of; external.

4. Computers. relating to a device or unit that is separate from but connected to a computer, network host, etc.

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noun

• peripherals
  plural

1. Computers.

   1. a device or unit that operates separately from the CPU but is connected to it, such as a mouse, printer, speakers, etc.

   2. a device or unit that is separate from a network’s host computer but in communication with it, such as a shared input terminal, printer, or backup drive.

peripheral British  

/ pəˈrɪfərəl /

adjective

1. not relating to the most important part of something; incidental, minor, or superficial

2. of, relating to, or of the nature of a periphery

3. anatomy of, relating to, or situated near the surface of the body

   a peripheral nerve

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peripheral Scientific  

/ pə-rĭf′ər-əl /

1. Anatomy Relating to or being the surface or outer part of a body or organ.

2. Relating to or being part of the peripheral nervous system.

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1. Computer Science An auxiliary device, such as a printer or modem, distinct from a computer's central processing unit and working memory, and often connected externally.

peripheral Cultural  

1. Any part that is separate from a computer's CPU, such as a printer, a keyboard, or a monitor.

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Other Word Forms

Derived Forms

• unperipheral
  adjective
• peripherally
  adverb

Inflected Forms

Nouns

• peripherals
  plural

Etymology

Origin of peripheral

First recorded in 1800–10; 1965–70 peripheral for def. 4; from Greek peripher(ḗs) ( see periphery ( def. )) + -al ¹ ( def. )

Explanation

Scanners, printers, and speakers are peripheral devices for a computer because they aren't central to the working of the computer itself. Anything peripheral is on the margin, or outside, while main things, like a computer's processor, are not peripheral. Outside of computer jargon, peripheral is a common term in eye exams, which measure peripheral vision to see how far toward the outer right and left edges you can see. Peripheral also describes nerves from the body's peripheral system, which are secondary to the main system but branch off of it — like the wires between peripheral devices and a computer.

Example Sentences

See Examples For:

peripheral peripherals

They plan to examine additional patient groups in future analyses, including people with chronic kidney disease and peripheral artery disease.

From Science Daily ● Aug. 10, 2026

“No forum is too small, technical or peripheral for careerist Chinese diplomats seeking recognition for defending Beijing’s position,” said Jacob Stokes, a senior fellow at the Washington-based Center for a New American Security think tank.

From The Wall Street Journal ● Jul. 20, 2026

Micron’s stock typically trades on the cheap because investors have long memories of dramatic cycles of supply and demand in the market for computer memory chips and peripheral devices.

From MarketWatch ● Jun. 26, 2026

John Stones is among the players who could benefit from more game time having played a peripheral role at Manchester City last season.

From BBC ● Jun. 9, 2026

She saw Rishi nodding in her peripheral vision.

From "When Dimple Met Rishi" by Sandhya Menon

Buried in the U.S. government’s consumer-price index is a category called ”computers, peripherals and smart-home assistant devices.”

From MarketWatch ● Aug. 15, 2026

Apple’s foray into services, its constant striving to anticipate any features and peripherals that might let another rectangle maker steal a march on the iPhone, are all about defending the gold mine.

From The Wall Street Journal ● May 8, 2026

Immediately after the fire took his home, Moore needed to work, but he no longer possessed the peripherals and equipment he required to record.

From Los Angeles Times ● Jan. 7, 2026

"Today, our AI glasses are phone peripherals," he said.

From Barron's ● Dec. 3, 2025

Some of the computer peripherals were already in boxes, but clothes and household stuff and books were scattered through every room.

From "Geeks: How Two Lost Boys Rode the Internet Out of Idaho" by Jon Katz

Related Words

• incidental
• tangential