Online dictionaries

Look it up

Here are some online dictionaries, thesauri, etc. you may find useful, with links to give you direct access:

Collins German Dictionary
A tried-and-tested classic, this has long been our choice among medium-sized bilingual dictionaries.
Leo, dict.cc, Beolingus
These were motivated by the idea of sharing information at no cost. They can be useful resources - particularly if you follow the tips below.

Not even the best dictionary deserves blind trust - and it can't possibly know what exactly you want to say. So always

check if the the context is right (e.g. try using Leo's filters under "Suchoptionen");
check the usage of suggested translations (e.g. by looking them up the other way round, and/or googling them).

Linguee
A combination of dictionary and search engine, based on a large corpus of translated texts. See how others have handled the same translation problem and pick the solution you like best.
IATE
The EU's mulilingual term base: if it's used in the EU institutions, you'll find it in there. As that is no small matter, it's well worth consulting the "Help" section before your first search.

Collins English Dictionary and English Thesaurus
A standard UK reference reseource
Merriam Webster
The American classic, comprising a general dictionary, a thesaurus, a medical dictionary and an encyclopedia, as well as plenty of other attractive features.
TheFreeDictionary
In addition to a general dictionary (based on the well-known American Heritage Dictionary), this offers specialised medical, legal and financial dictionaries (all US-based), as well as sections on acronyms and idioms.

... nor are they free. Still, we wouldn't want to do without them:

Langenscheidt Muret-Sanders Großwörterbuch Englisch (4 volumes, incl. CD-Rom)
With a total of over 770,000 translations, this is the most comprehensive G-E/E-G dictionary available. Read more.
Collins COBUILD Advanced Learner's English Dictionary (1 volume, incl. CD-Rom)
We think this is simply the best E-E learner's dictionary of all. The unique COBUILD data base gives users access to real English. Read more.
(Collins COBUILD Advanced Dictionary of English is a learner's dictionary App for iPhone and iPad. Read more.)
Dietl/Lorenz: Wörterbuch für Recht, Wirtschaft und Politik (2 volumes, G-E/E-G, incl. CD-Rom)
In our opinion the best of its kind, too - however, the new edition is a long time coming. Read more.