- a river in S central Europe, flowing E and SE from the Alps in S Austria, through NE Slovenia, along a part of the border between Hungary and Croatia into the Danube in Croatia. 450 miles (725 km) long.
- a river in S central Europe, rising in N Italy and flowing east through Austria, then southeast along the southern Hungarian border to join the River Danube. Length: 725 km (450 miles)
