Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
2. Lăres, ĭum, f., a city in Numidia, Sall. J. 90 Kritz N. cr.
Lārĭus, ii, m., a lake in Gallia Cisalpina, on which Comum lay, now Lago di Como, Verg. G. 2, 159; Plin. Ep. 9, 7, 1; Plin. 3, 19, 23, § 131.
Hence, Lārĭus, a, um, adj., of Larius, Larian: Larium litus, Cat. 35, 4.