a freedman of T. Pomponius Atticus, received his nomen from Atticus, his former master, according to the usual custom, but had the praenomen Marcus given him in compliment to M. Tullius Cicero (Cic. Att. 4.15, comp. 4.8, 11, 13). It is erroneously stated in Vol. I. p. 1039a. init. that his full name was T. Pomponius Dionysius.
A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890