Nāsĭdĭus: a,I name of a Roman gens. 1 L. Nasidius, a Roman knight, Cic. Phil. 7, 8, 24.— 2 An adherent of Pompey, Caes. B. C. 2, 3; Cic. Att. 11, 17, 3.—Hence, Nā-sĭdĭānus, a, um, adj., Nasidian: naves, Caes. B. C. 2, 7.