Lewis & Short

Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.

Lūsĭtānĭa, ae, f., the western part of Spain, the mod. Portugal and a part of the Spanish provinces of Estremadura and Toledo, Caes. B. C. 1, 38, 2; Liv. 21, 43, 8; 27, 20; Mel. 2, 6, 3 sq.; 3, 1, 6; 3, 6, 2; Liv. Ep. 52; Plin. 4, 21, 35, § 113.
Hence, Lū-sĭtānus, a, um, adj., of or belonging to Lusitania, Lusitanian: cerasa, Plin. 15, 25, 30, § 103: tela, Val. Max. 9, 1, n. 5.
In plur. subst.: Lūsĭtāni, ōrum, m., the Lusitanians, Cic. Brut. 23, 89; Liv. 35, 1; 37, 46 sq.; Plin. 4, 22, 35, § 116.