1. Related to, located in, or constituting an outer boundary or periphery.
2. Perceived or perceiving near the outer edges of the retina: peripheral vision.
a. Of the surface or outer part of a body or organ; external.
b. Of, relating to, or being part of the peripheral nervous system.
4. Of minor relevance or importance.
An auxiliary device, such as a printer, modem, or storage system, that works in conjunction with a computer.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.