One Look

http://www.onelook.com/



Oxford dictionaries

http://oxforddictionaries.com/?attempted=true

 


The Longman Dictionary of Contemporary

 English Online

http://www.ldoceonline.com/

 


Cambridge Dictionaries Online

http://dictionary.cambridge.org/

 

Merriam Webster Online

http://www.merriam-webster.com/


Free Dictionary

http://www.thefreedictionary.com/

 


Britannica

http://www.britannica.com/