Danube
WordNet
noun
(1) The 2nd longest European river (after the Volga); flows from southwestern Germany to the Black Sea
"Vienna, Budapest, and Belgrade are on the banks of the Danube"
WiktionaryText
Etymology
From Latin Dānubius, from Celtic Danuvios, akin to the Welsh river name Donwy, from Pre-Celtic *Dāne/owjos, from Indo-European *dhen 'run, flow', akin to Latin fōns 'spring', Persian danīdan 'to hasten, run', Ossetian don 'water', Sanskrit dhánvati 'it flows, runs'.