Lewis & Short

autŏgrăphus, a, um, adj., = αὐτόγραφος, written with one’s own hand, autograph: Autographā quādam epistulā Cenavi, ait, mi Tiberi, cum īsdem, Suet. Aug. 71: litterae, id. ib. 87.
Also subst.: autŏ-grăphum, i, n., an autograph, Symm. Ep. 3, 11.