English matters (NTNU)
Online resource for Norwegians studying or working in English. Links include dictionaries of political and professional jargon (Norwegian-English), as well as English academic writing guides, dictionaries, newspapers, and writing exercises.

Dictionaries for international visitors learning Norwegian. Made available for free by the Norwegian Directorate for Education and Training. Available in either Bokmål or Nynorsk and translated into nearly 20 different languages including English, Arabic, Thai and Polish.

Norwegian dictionaries from the publisher Kunnskapsforlaget. 
Foreign language dictionaries: English, German, French, Italian, Spanish.
Medical dictionaries in Norwegian and English.

Oxford English Dictionary
The most comprehensive and up-to-date dictionary for the English language. Shows the origins, history and use of over 600,000 words through 3 million citations from a wide selection of authoritative sources. Also includes timelines and historical thesauruses.

UHRs Termbase English-Norwegian / Norwegian-English
Online dictionary with over 1000 English-Norwegian/Norwegian-English administrative terms from the university and college sector.