Cambridge Dictionary is described as 'multi-language dictionary for students and people who are in contact with English. This online version has been offering completely free of charge since 1999 by the Univeristy of Cambridge' and is a Dictionary in the Education & Reference category. There are more than 10 alternatives to Cambridge Dictionary, not only websites but also apps for a variety of platforms, including iPhone, Android, iPad and Chrome OS. The best alternative is Merriam-Webster, which is free. Other great sites and apps similar to Cambridge Dictionary are Dictionary.com (Free), Thesaurus.com (Free), The Free Dictionary (Freemium) and Oxford Dictionaries (Free).
Online Dictionary - Multiple dictionaries including: English dictionary, medical dictionary, legal dictionary, financial dictionary, computer dictionary, thesaurus, dictionary of acronyms and abbreviations, dictionary of idioms, thesaurus, Columbia encyclopedia, Wikipedia...
Free online dictionary of British English and American English from Oxford. Translate from English to Spanish, French, Italian, and German with bilingual dictionaries. Get writing, spelling and grammar help, and play word games.
Advanced English Dictionary is better than other dictionaries, not just because it contains far more words than a conventional paper dictionary, but because it uses a radically new approach to searching for words.