METAURUS (mod. Metauro; the form Mataurus is later, and is more frequent in inscriptions of the imperial period), a river of Italy, which flows into the sea a little south-east of Fanum Fortunae (mod. Fano). On its banks Hasdrubal, while marching to the aid of Hannibal in 207 B.C., was defeated and slain by the Roman army, this being the decisive battle of the Second Punic War. The exact site of the battle is uncertain; tradition places it between Fossombrone and the Furlo Pass, but it is probable that it occurred nearer the sea-coast.