river in S Europe, flowing from the Black Forest in S Germany eastward into the Black Sea: c. 1,770 mi (2,850 km): Bulg. name Dunav, Czech name Dunaj, Ger. name Donau, Hung. name Duna, Romanian name Dunărea, Russ. name Dunai
A river of south-central Europe rising in southwest Germany and flowing about 2,848 km (1,770 mi) southeast through Austria, Hungary, Serbia, and Romania to the Black Sea. It has been a major trade route since the Middle Ages.