The Duden (German pronunciation: [ˈduːdən]) is a dictionary of the German language, first published by Konrad Duden in 1880. The Duden is updated regularly, with new editions appearing every four or five years. As of August 2013 it is in its 26th edition and in 12 volumes, each covering different aspects such as loanwords, etymology, pronunciation, synonyms, etc.
The first of these volumes, Die deutsche Rechtschreibung (English: German Orthography), has long been the prescriptive source for the spelling of German. The Duden has become the bible of the German language, being the definitive set of...