Other dictionaries and databases of terminology
Multifunctional dictionary, thesaurus and encyclopaedia
Collection of multilingual dictionaries
Foreign language online dictionaries and free translation
Foreign language online dictionaries with focus on Germanic languages
Links to dictionaries and language resources
Links to multiple specialised dictionaries
Dictionary of 134,000 acronyms
Ask Oxford Dictionaries - including all sorts of tips on grammar
Online Dictionary Database Query - lists word derivatives, etc.
Common Errors in English - difficult words in English