(anc. Aufidus), a river of Italy, in the Kingdom of Naples, rises in the Apennines, province of Principato Ultra, flows E.N.E., separating Capitanata from Basilicata and Bari, and falls into the Adriatic, after a course of 75 miles. On the right bank is the field of the battle of Cannae, where the Romans were totally defeated by Hannibal, n.c. 216.