- a combining form meaning “self,” “same,” “spontaneous,” used in the formation of compound words: autograph, autodidact.
Origin of auto-1
- a combining form representing automobile in compound words: autocade.
Origin of auto-2
- a combining form representing automatic in compound words: autoalarm; autofeed; autofocus. Sometimes also taken as an adjective: auto enlarger; auto stop control; auto dialer.
sometimes before a vowel aut-
- self; same; of or by the same oneautobiography
- acting from or occurring within; self-causedautohypnosis
- self-propelling; automaticautomobile
Word Origin and History for 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-.
- Self; same:autogamy.
- 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.