See more synonyms for auto on
  1. of or relating to automobiles: an auto salesman; auto detailing.

Origin of auto

An Americanism dating back to 1895–1900; by shortening



  1. a combining form meaning “self,” “same,” “spontaneous,” used in the formation of compound words: autograph, autodidact.
Also especially before a vowel, aut-.

Origin of auto-

< Greek, combining form of autós self


  1. a combining form representing automobile in compound words: autocade.

Origin of auto-

see origin at auto


  1. a combining form representing automatic in compound words: autoalarm; autofeed; autofocus. Sometimes also taken as an adjective: auto enlarger; auto stop control; auto dialer. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for auto

car, vehicle, wheels

Examples from the Web for auto

Contemporary Examples of auto

Historical Examples of auto

British Dictionary definitions for auto


noun plural -tos US and Canadian informal
    1. short for automobile
    2. (as modifier)auto parts
  1. Indian informal short for autorickshaw


sometimes before a vowel aut-

combining form
  1. self; same; of or by the same oneautobiography
  2. acting from or occurring within; self-causedautohypnosis
  3. self-propelling; automaticautomobile

Word Origin for auto-

from Greek autos self
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 auto

shortened form of automobile, 1899; cf. French auto.


word-forming element meaning "self, one's own, by oneself," from Greek auto- "self, one's own," combining form of autos "self, same," of unknown origin. Before a vowel, aut-; before an aspirate, auth-. In Greek also used as a prefix to proper names, e.g. automelinna "Melinna herself." The opposite prefix would be allo-.

Online Etymology Dictionary, © 2010 Douglas Harper

auto in Medicine


  1. Self; same:autogamy.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

auto in Science


  1. A prefix meaning “oneself,” as in autoimmune, producing antibodies or immunity against oneself. It also means “by itself, automatic,” as in autonomic, governing by itself.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.