Online Dictionaires
German-English dictionary
Beolingus - TU Chemnitz
A dictionary from the Technische Universität Chemnitz.
German-English dictionary
Leo
Originally a service of the Fachbereich "Informatik" of the Technische Universität München.
Probably the best-known online dictionary, but not infallible! There is also an app available for smartphones.
German-English dictionary
Dict.cc
A contributor based dictionary. There is also an app available for smartphones.
German-English dictionary
Quickdic
A German-English dictionary with more than 300,000 words and Idioms in each language.
English-English learner's dictionary
Oxford
A dictionary specifically for learners of English from the well known Oxford Publishers.
https://www.oxfordlearnersdictionaries.com
English-English learner's dictionary
Longman
An excellent dictionary specifically for learners of English.
English-English dictionary and thesaurus
Dictionary.com
A dictionary/thesaurus that also offers a free app for iOs and Android smart phones.
English-English dictionary and thesaurus
Merriam-Webster
A dictionary/thesaurus with quizzes and videos.
http://www.merriam-webster.com/
English-English dictionary
Your Dictionary
A dictionary with pictures,example sentences and a synonym thesaurus.
http://www.yourdictionary.com/
English-English dictionary
The Free Dictionary by Farlex
Includes links to specialised online dictionaries (medical, financial, legal) and has a homepage with games etc. that you can customise.
http://www.thefreedictionary.com/
Pronunciation
Howjsay.com
Free online talking dictionary of English pronunciation.
A reverse dictionary
OneLook
Find a list of words related to your search-word or description.