peripheral

UK: /pəˈrɪf^ərəl/ US: /pəˈrɪfərəl/ ,(pə rif′ər əl)

WordReference Random House Learner's Dictionary of American English © 2025

pe•riph•er•al /pəˈrɪfərəl/   adj. 

1. of or relating to the periphery:
   the peripheral boundaries.
2. concerned with less central aspects of a problem or situation:
   questions peripheral to the main issue.
3. Computing of or relating to a computer peripheral:
   [before a noun] buying peripheral devices.

n. [countable]

4. Computing a device, as a keyboard, printer, or tape drive, that is outside a computer but connected to it.

WordReference Random House Unabridged Dictionary of American English © 2025

pe•riph•er•al  (pə rif′ər əl), adj. 

1. pertaining 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. Computing of or pertaining to a peripheral.

n. 

5. Computing a device or unit that operates separately from the CPU but is connected to it, as a magnetic disk or tape unit or a printer.

Also, peripheric (for defs. 1–3).

• Greek peripher(é̄s) (see periphery) + -al¹
• 1800–10; 1965–70 for def. 4;

pe•riph′er•al•ly, adv. 

Collins Concise English Dictionary © HarperCollins Publishers::

peripheral / 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. of, relating to, or situated near the surface of the body: a peripheral nerve
   Also: peripheric, peripherical

peˈripherally adverb