or a·dap·tor

  1. a person or thing that adapts.
    1. a connector for joining parts or devices having different sizes, designs, etc., enabling them to be fitted or to work together.
    2. Also called plug adapter, adapter plug.a device that connects an electrical plug to an outlet that has a different plug shape: Last time I traveled, I brought the wrong adapter.
    3. Also called AC adapter, power adapter.a device with a cord that plugs into an electrical outlet and functions as an external power supply for a small or portable electronic device, usually converting AC current to DC: I forgot to plug in the adapter, and my laptop died.
  2. an accessory to convert a machine, tool, or part to a new or modified use.
  3. Computers.
    1. expansion card.
    2. an external device containing the necessary circuitry to connect to or work with another device or system: a network adapter; a wireless adapter; a video adapter.

Origin of adapter

First recorded in 1795–1805; adapt + -er1
Related formsnon·a·dapt·er, non·a·dap·tor, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for adaptor

Historical Examples of adaptor

  • The adaptor piece may have a face mould worked upon it to give a pilaster-like appearance if fancy so dictates.

    Woodwork Joints

    William Fairham

  • The artist and the adaptor have still hardly begun to work with the endless variety of substances now at their disposal.

  • He is styled the inventor of the velvet pile in tapestry, but it were better to call him the adaptor.

    The Tapestry Book

    Helen Churchill Candee

  • We can do some of these things by apparatus designed by the brain of man—and man really is but an imitator and adaptor of Nature.

  • The adaptor deserves great credit for altering as little as possible.

British Dictionary definitions for adaptor



  1. a person or thing that adapts
  2. any device for connecting two parts, esp ones that are of different sizes or have different mating fitments
    1. a plug used to connect an electrical device to a mains supply when they have different types of terminals
    2. a device used to connect several electrical appliances to a single mains socket
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 adaptor



1801, agent noun from adapt. Electrical engineering sense from 1907.

Online Etymology Dictionary, © 2010 Douglas Harper

adaptor in Medicine


  1. One that adapts.
  2. A connecting part that joins two pieces of apparatus.
  3. A converter of electric current to a desired form.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.