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

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

Its six LEDs combine three narrow beams with three wide ones at a 23-degree angle, casting a 1,300-lumen punch that lights up about 390 feet (120 m) downrange while still keeping your peripheral lit. —Joe Salas october 09, New Atlas, 9 Oct. 2025

The trio had, in research dating back two decades, uncovered a key pathway the body uses to keep the immune system in check, called peripheral immune tolerance. —Jessica Coacci, Fortune, 8 Oct. 2025

Noun

Finally, for connectivity, this is an all-USB-Type-C device for peripherals and video-out options, with two such ports on the left and one more on the right. —Matthew Buzzi, PC Magazine, 5 Oct. 2025

Angle for a more well-rounded threat here, and try to circle back later in the draft; if not, Weegar’s peripherals could be made up for elsewhere. —Shayna Goldman, New York Times, 30 Sep. 2025

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