(anc. geog.), a river of Umbria, on this side the Apennine. According to Pliny, it was a fountain consisting of several veins, situated between Hissellum and Spoletium; which soon after swelled into a very large and navigable river, running from east to west into the Tiber, and both together into the Tiber. A river famous for its milk-white flocks and herds, (Virgil.) The god of the river was called Clitumnus.