Reference » Dictionaries
Merriam-Webster - http://www.merriam-webster.com/
Features a free online dictionary, thesaurus, Spanish-English and medical dictionaries, audio pronunciations, Word of the Day, word games, and many more high-quality Merriam-Webster language resources.
YourDictionary - http://www.yourdictionary.com/
A free online dictionary that offers definition search from Webster's dictionary for word meanings and thesaurus.