the chief coalmining and industrial region of Germany: in North Rhine-Westphalia around the valley of the River Ruhr (a tributary of the Rhine 235 km (146 miles) long)
German name: Ruhrgebiet (ˈruːrɡəˌbiːt)
Ruhr in American English
(rʊr; German ˈʀuəʀ)
1.
river in WC Germany, flowing west into the Rhine: 145 mi (233 km)
2.
major coal-mining & industrial region centered in the valley of this river