[puh-rif-er-uh l]

adjective Also peripheric (for defs 1–3).

pertaining to, situated in, or constituting the periphery: peripheral resistance on the outskirts of the battle area.
concerned with relatively minor, irrelevant, or superficial aspects of the subject in question.
Anatomy. near the surface or outside of; external.
Computers. of or relating to a peripheral.


Computers. 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.

Nearby words

  1. peripatetic,
  2. peripatetics,
  3. peripatus,
  4. peripeteia,
  5. peripherad,
  6. peripheral device,
  7. peripheral dysostosis,
  8. peripheral motor neuron,
  9. peripheral nervous system,
  10. peripheral ossifying fibroma

Origin of peripheral

1800–10; 1965–70 for def 4; < Greek peripher(ḗs) (see periphery) + -al1

Related formspe·riph·er·al·ly, adverbun·pe·riph·er·al, adjectiveun·pe·riph·er·al·ly, adverb Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for peripheral

British Dictionary definitions for peripheral



not relating to the most important part of something; incidental, minor, or superficial
of, relating to, or of the nature of a periphery
anatomy of, relating to, or situated near the surface of the bodya peripheral nerve
Derived Formsperipherally, adverb

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for peripheral



1803, from periphery + -al (1). An earlier formation was peripherial (1670s). Related: Peripherally. As a noun, peripherals, "peripheral devices of a computer," is from 1966.

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for peripheral




Related to, located in, or constituting an outer boundary or periphery.
Perceived or perceiving near the outer edges of the retina.
Of or relating to the surface or outer part of a body or organ; external.
Of, relating to, or being part of the peripheral nervous system.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for peripheral




Anatomy Relating to or being the surface or outer part of a body or organ.
Relating to or being part of the peripheral nervous system.


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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Culture definitions for peripheral


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

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.