Pronunciation: (ô'tō), [key]
a combining form meaning “self,” “same,” “spontaneous,” used in the formation of compound words: autograph. Also, esp. before a vowel,aut-.
a combining form representing automobile in compound words: autocade.
a combining form representing automatic in compound words: autoalarm; autofeed; autofocus. Sometimes also taken as an adjective: auto enlarger; auto stop control.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.