peripheral

1 of 2

adjective

pe·​riph·​er·​al pə-ˈri-f(ə-)rəl 

1

: of, relating to, involving, or forming a periphery or surface part

2

a

: of, relating to, affecting, or being part of the peripheral nervous system

peripheral nerves

peripheral neuritis

b

: of, relating to, or being blood in the systemic circulation

peripheral lymphocytes

3

: of, relating to, or being the outer part of the field of vision

good peripheral vision

4

: auxiliary, supplementary

peripheral equipment

also : of or relating to computer peripherals

peripherally adverb

peripheral

2 of 2

noun

: a device connected to a computer to provide communication (such as input and output) or auxiliary functions (such as additional storage)

Did you know?

Your peripheral vision is the outer area of your field of vision, where you can still detect movement and shapes. It can be very valuable when, for instance, you're driving into Chicago at rush hour, especially when switching lanes. When people call an issue in a discussion peripheral, they mean that it's not of primary importance, and they're probably suggesting that everyone get back to the main topic. Peripheral is now also a noun: computer peripherals are the added components—printers, webcams, microphones, etc.—that increase a computer's capacities.

Synonyms of peripheral

Adjective

• auxiliary
• additional
• accessory

Examples of peripheral in a Sentence

Adjective

If we focus too much on peripheral issues, we will lose sight of the goal.

peripheral devices such as modems and scanners

He saw in his peripheral vision that a car was trying to pass him.

Recent Examples on the Web

Adjective

Inner circle role Within that system, prosecutors portray Maduro not as a peripheral figure but as a central architect. —Antonio María Delgado, Miami Herald, 20 Mar. 2026

The guardians of knowledge have customarily deemed the history and experience of Asian Americans to be inessential or peripheral to all levels of American education. —Literary Hub, 16 Mar. 2026

Noun

The bundled keyboard and mouse are also decent, and there are plenty of ports for extra peripherals. —K. Thor Jensen, PC Magazine, 27 Mar. 2026

That'll sort out all but the most ambitious of tablet computing setups, complete with an external display and a host of peripherals – in addition to a stylus, mouse, and keyboard that can pair via Bluetooth. —New Atlas, 24 Mar. 2026

Word History

First Known Use

Adjective

1808, in the meaning defined at sense 1

Noun

1966, in the meaning defined above

Phrases Containing peripheral

• peripheral nervous system
• peripheral neuropathy

Kids Definition

peripheral

1 of 2 adjective

pe·​riph·​er·​al pə-ˈrif-(ə-)rəl 

1

: of, relating to, located in, or forming a periphery

2

: auxiliary entry 1, supplementary

peripheral equipment

peripherally

-ē

adverb

peripheral

2 of 2 noun

: a device connected to a computer to provide communication (as input and output) or extra storage capacity

Medical Definition

peripheral

adjective

pe·​riph·​er·​al pə-ˈrif-(ə-)rəl 

1

: of, relating to, involving, forming, or located near a periphery or surface part (as of the body)

2

: of, relating to, affecting, or being part of the peripheral nervous system

peripheral nerves

3

: of, relating to, or being the outer part of the visual field

good peripheral vision

4

: of, relating to, or being blood in the systemic circulation

peripheral lymphocytes

peripheral blood

peripherally

-ē 

adverb