Lewis & Short

Samnĭum, ii, n. [contr. from Sabinium, from Sabini: ab Sabinis orti Samnites, Varr. L. L. 7, § 29 Müll.], an ancient country of Italy, in the neighborhood of Latium, whose inhabitants were an offshoot from the Sabines, Liv. 7, 32; Cic. Clu. 69, 197; id. Att. 14, 20, 2; 16, 11, 6; id. Rep. 3, 7 al.
Hence,

  1. A. Samnīs (collat. form of the nom. Samnītis, Cato ap. Prisc. p. 762; Prud. adv. Symm. 2, 515), ītis, adj., of or belonging to Samnium, Samnite: ager, Liv. 24, 20: exercitus, id. 10, 16 fin.: bellum, Plin. 34, 6, 12, § 26: ursae, Sil. 4, 560: habitator Samnitis (terrae), Prud. στεφ. 11, 207.
    Subst., in plur.: Samnītes, ĭum (gen. Samnitum, Cic. de Or. 2, 79; but cf. Samnitium, id. ib. 3, 23 Orell. N. cr.; and so usu. and very freq. in Liv., Plin., and Tac.), m., the inhabitants of Samnium, the Samnites, Varr. L. L. 7, 3, 86 fin.; Liv. 7, 19; 7, 29 sq.; 8, 1 sq.; 9, 1 sq.; Cic. Off. 1, 12, 38; 3, 30, 109; id. Sen. 16, 55 al.
    Gr. acc. Samnităs, Flor. 1, 16, 7; Aur. Vict. Vir. Ill. 34, § 6.
    In sing.: Samnīs, ītis, m., collect., the Samnites, Liv. 10, 35; Luc. 2, 137.
    1. 2. Transf., the name of Samnites was also given to a class of gladiators who were armed with Samnite weapons, Varr. L. L. 5, § 142 Müll.; Plin. 7, 20, 19, § 81; Liv. 9, 40; Cic. de Or. 2, 80, 325; 3, 23, 86; Inscr. Orell. 2569.
      So in sing.: Samnīs, Lucil. ap. Cic. Tusc. 2, 17, 41; and ap. de Or. 3, 23, 86.
  2. B. Samnītĭcus, a, um, adj., Samnite: bellum, Suet. Vit. 1; Flor. 1, 16, 2: vasa, Capitol. Pertin. 8.