ARTFL Webster
ARTFL Webster
http://humanities.uchicago.edu/forms_unrest/webster.form.html
American Heritage
The american heritage dictionary of the english language, fourth edition. 2000
http://www.bartleby.com/61/
Dictionary.com
Dictionary.com
http://www.dictionary.com/
Majstro
Majstro
http://www.majstro.com/
Van Dale
Van Dale
http://www.vandale.nl/
YourDictionary
Yourdictionary - comprehensive authoritative dictionary, thesaurus, glossary and foreign language portal. every resource needed for language study in more than 300 languages.
http://www.yourdictionary.com/