1) German surname 
The Duden (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. T...