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

Once the peripheral immune cells entered the brain, they transformed into specialized microglia.

From Science Daily ● Aug. 14, 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

"The growing international support for these conversations demonstrates that reparatory justice is no longer a peripheral issue," Ghana's foreign minister said.

From Barron's ● Jun. 18, 2026

In her peripheral vision, Rishi looked up at her and then back down again.

From "When Dimple Met Rishi" by Sandhya Menon

The low P/E for Sandisk and Micron reflect investors’ concerns over the cyclical nature of the semiconductor industry, and computer memory chips and peripherals in particular.

From MarketWatch ● Aug. 10, 2026

The modest rise in June imports was led by computers and computer peripherals, without which inbound shipments would have fallen 1.3% for the month.

From The Wall Street Journal ● Aug. 4, 2026

The first AI category is investment into the computers, peripherals and networking equipment that fill these data centers, which grew by 61% annualized from the previous quarter.

From Barron's ● Feb. 20, 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

In the peripherals of my vision, the Hebrew letters on signs seemed to change, distorting into an alphabet I had never learned.

From "The City Beautiful" by Aden Polydoros

Related Words

• incidental
• tangential