Lewis & Short

Īgŭvĭum, ĭi, n., a city of Umbria, now Gubbio, Cic. Att. 7, 13, b, 6; Caes. B. C. 1, 12; Liv. 45, 43; Sil. 8, 461.
Hence, Īgŭ-vĭnātes, ium, m., its inhabitants, Cic. Balb. 20, 47; and Īgŭvīni, ōrum, m., Caes. B. C. 1, 12; Plin. 15, 7, 7, § 31; and Iguini, id. 3, 14, 19, § 113.