Dictionary.com
definitions

Danube

[dan-yoob]
noun
  1. a river in central and SE Europe, flowing E from southern Germany to the Black Sea. 1725 miles (2775 km) long.
German Donau.Hungarian Duna.Czech and Slovak Dunaj.Romanian Dunărea.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for danube river

Danube

noun
  1. a river in central and SE Europe, rising in the Black Forest in Germany and flowing to the Black Sea. Length: 2859 km (1776 miles)German name: Donau Czech name: Dunaj Hungarian name: Duna Croatian and Serbian name: Dunav (ˈdunaf) Romanian name: Dunărea
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for danube river

Danube

major river of Europe (German Donau, Hungarian Duna, Russian Dunaj), from Latin Danuvius, from Celtic *danu(w)-yo-, from PIE *danu- "river" (cf. Don, Dnieper, Dniester).

Online Etymology Dictionary, © 2010 Douglas Harper
danube river in Culture

Danube River

River in central and southeastern Europe.

Note

Flowing for nearly two thousand miles, it is the second-longest European river, after the Volga.

Note

Composer Johann Strauss, the Younger, expressed the charm and romance of the river in his “Blue Danube Waltz.”
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.