Few people now go to the bookstore for the dictionary, online dictionaries are no worse, and in addition faster and free. SpeakStarter has prepared for you a selection of online dictionaries of the German language:
Duden
The first and most important is Duden. Duden is a dictionary and a set of rules for grammar and spelling of the German language. Previously, the dictionary defined the official spelling of the German language in Germany. Now its sphere of influence is limited, but for those who study literary German it still remains the standard. This dictionary has absolutely all variants of word meaning and for each variant there is an example of usage.
duden.de
Wiktionaty.de
The second German service is the German Wiktionary. It is not as authoritative as duden, but can be used as a supplement to it. On Wiktionaty.de it is very convenient to look at the plural of nouns, the three forms of the verb or the verb conjugation. As in Duden, there are examples of usage.
Dict.leo.org
This dictionary is one of the most complete when it comes to translation from Russian into German. It includes usage examples and derivatives of the word (for example, a noun from a verb, etc.). In general, we use it ourselves and advise everyone.
There are no such good Russian-German dictionaries as the English-German ones. But for those who don’t know English or German enough to use an explanatory dictionary we will offer such Russian-German dictionaries:
dict.cc
lingvo-online.ru
babla.ru
You can look at any of them, try which dictionary you like or which interface you find more convenient.