a river in central Europe, rising in the NE Czech Republic and flowing north and west, forming part of the border between Germany and Poland, to the Baltic. Length: 913 km (567 miles)
Czech and Polish name: Odra
Oder in American English
(ˈoʊdər)
river in central Europe, flowing north through Czech Republic & Poland into the Baltic:c. 560 mi (901 km): it forms, with the Neisse, the boundary (Oder-Neisse Line) between Germany & Poland