dĭădēmātus, a, um, adj. [diadema],
adorned with a diadem : Apollo, Plin. 34, 8, 19, § 79. —Hence,
Dĭădēmātus, i, m., a Roman surname , Cic. Post. Red. ad Quir. 3, 6. ...
A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.