Lewis & Short

gentĭlīcĭus or -tĭus, a, um, adj. [gentilis].

  1. I. Of or belonging to a particular clan or gens (class.; cf. gentilis): an gentilicia sacra ne in bello quidem intermitti, publica sacra et Romanos deos etiam in pace deseri placet? Liv. 5, 52, 4; v. sacrum, under sacer: sacrificia, Auct. Or. de Harusp. Resp. 15: gentilicia (nota), opp. publica, Liv. 6, 20, 14: tumulus, a family sepulchre, Vell. 2, 119, 5: hereditates, Suet. Caes. 1: nomina, id. Claud. 25: M. Varro tradit, in Serranorum familia gentilicium esse, feminas linea veste non uti, Plin. 19, 1, 2, § 8; Plin. Ep. 6, 15, 1.
  2. II. Of or belonging to a nation, national (post-class.): vulgus, quos gentilicio vocabulo Chaldaeos dicere oportet, mathematicos dicit, by their national name, Gell. 1, 9, 6.