English Dictionaries
Chambers 21st Century Dictionary «select Chambers 21st Century Dictionary from the drop down menu
Online Etymology Dictionary «explanations of word origins from Douglas Harper
Oxford English Dictionary (Compact)
The Free Dictionary «traditional English dictionary as well as acronym, idiom, and subject dictionaries
WordNet «project from Princeton's Cognitive Science Laboratory
YourDictionary.com « offers free access to several dictionaries, including thesauri and specialty dictionaries
English Thesauri
The Chambers Thesaurus (1996) «select Chambers Thesaurus from the drop down menu
Roget's II: The New Thesaurus (1995)
Roget's International Thesaurus of English Words and Phrases (1922)
Non-English Dictionaries
Alpha Dictionary «guide to online dictionaries for several hundred languages
Arabic
Sakhr «English-Arabic dictionary from Sakhr Software Company
Edward William Lane's Arabic English Lexicon «3200 page Arabic-English dictionary available as PDF files
Chinese
Chinese English Center «Chinese-English dictionary from the University of Maine
French
The Artful Project «French-English dictionary from the University of Chicago
German
BeoLingus «German-English dictionary provided by TU Chemnitz
Italian
Collins Online Dictionary «Italian-English dictionary provided by Collins Reference (HarperCollins)
WordReference «Italian-English dictionary from Michael Kellogg
Japanese
Dima Chirkin «Japanese-English dictionary from Dmitry Chirkin of UC Berkeley
Japanese Dictionary Server «project from Jim Breen of Monash University in Australia
Russian
Dima Chirkin «Russian-English dictionary from Dmitry Chirkin of UC Berkeley
Spanish
Word Reference «Spanish-English dictionary from Michael Kellogg