autographyoudaoicibaDictYouDict[autograph 词源字典]
autograph: [17] Greek auto- was a prefixal use of the adjective autós, meaning ‘same, self’. Many of the commonest auto- words in English, including autograph itself and also autocrat [19], automatic [18] (a derivative of automaton [17], which was formed from a hypothetical base *men- ‘think’ related to mental and mind), autonomy [17], and autopsy [17] (originally meaning ‘eye-witness’, and derived from Greek optós ‘seen’, source of English optic), are original Greek formations.

But the 19th and particularly the 20th century have seen a mass of new coinages, notably in scientific and technical terminology, including such familiar words as autism, autobiography, autoerotic, autofocus, autogiro, autoimmune, automotive, autosuggestion, and of course automobile (originally a French formation of the 1870s). Automobile has itself, of course, given rise to a completely new use for the auto- prefix, with the general connotation of ‘motorized transport’, as in autobus, autocar, autocycle, and the German autobahn.
[autograph etymology, autograph origin, 英语词源]
autograph (n.)youdaoicibaDictYouDict
"a person's signature," 1791, from Latin autographum, from Greek autographon, neuter of autographos "written with one's own hand," from autos- "self" (see auto-) + graphein "to write" (originally "to scratch;" see -graphy). Used earlier (1640s) to mean "author's own manuscript."
autograph (v.)youdaoicibaDictYouDict
"to sign one's name," 1837, from autograph (n.). Related: Autographed; autographing. Earlier "to write with one's own hand" (1818).