short for automobile - (as modifier): auto parts
WordReference Random House Learner's Dictionary of American English © 2026
au•to /ˈɔtoʊ/USA pronunciation
n. [countable], pl. -tos.
auto-1 , prefix.
auto-3 ,
WordReference Random House Unabridged Dictionary of American English © 2026- an automobile.
auto-1 , prefix.
- auto- comes from Greek, where it has the meaning "self.'' This meaning is found in such words as: autocrat, autograph, autonomous, autonomy, autopsy. Also, esp. before a vowel, aut-.
auto-3 ,
au•to
(ô′tō),USA pronunciation n., pl. -tos.
auto-1 ,
auto-2 ,
auto-3 ,
auto. ,
- automobile.
- by shortening 1895–1900, American.
auto-1 ,
- a combining form meaning "self,'' "same,'' "spontaneous,'' used in the formation of compound words:autograph.Also,[esp. before a vowel,] aut-.
- Greek, combining form of autós self
auto-2 ,
- a combining form representing automobile in compound words:autocade.
- see auto
auto-3 ,
- a combining form representing automatic in compound words:autoalarm;autofeed;autofocus.Sometimes also taken as an adjective:auto enlarger; auto stop control.
auto. ,
- automatic.
- automobile.
- automotive.
Collins Concise English Dictionary © HarperCollins Publishers::
auto /ˈɔːtəʊ/ n ( pl -tos) US Canadian informal
Collins Concise English Dictionary © HarperCollins Publishers::
auto-, (sometimes before a vowel) aut- combining form
- self; same; of or by the same one: autobiography
- acting from or occurring within; self-caused: autohypnosis
- self-propelling; automatic: automobile
'auto' also found in these entries (note: many are not synonyms or translations):
aut-
- autarchy
- autarky
- authentic
- auto-
- autobahn
- autochthon
- autoclave
- auto-da-fé
- autonomous
- autopsy
- auto-repeat
- autoroute
- autostrada
- Canetti
- CAW
- tauto-
- accelerator
- act of faith
- advance
- air dam
- antiroll bar
- antiskid
- antisway bar
- author
- autoanalysis
- autoanalyzer
- autoantibody
- autoantigen
- autobiographical
- autobiography
- autobus
- autocade
- autocatalysis
- autocatharsis
- autocephalous
- autochrome
- autocide
- autocollimation
- autocollimator
- autocorrelation
- auto court
- autocrat
- autocross
- auto-destruct
- auto-dial
- auto-dialer
- autodidact
- autodyne
- autoerotic