Root word dictionary (Greek & Latin)
Name origins http://www.behindthename.com/
Word origins http://oxforddictionaries.com/words/word-origins
Merriam-Webster Dictionary http://www.merriam-webster.com/
Cambridge Dictionary & Thesaurus http://dictionary.cambridge.org/us/
One Look Dictionary http://www.onelook.com/
Dictionary of Medieval Names http://dmnes.org/about
ONLINE DICTIONARIES - All Words
Allwords.com Has the traditional dictionary feature along with specialized word searches and translations.
Bartleby.com A site worth the time to explore it. Contains a myriad of features for writers that include a dictionary, a thesausus, an encyclopedia, an English usage book, and a style book.
Dictionary.com Contains a dictionary, thesausus, and encyclopedia features amoung others.
Encarta.msn.com Includes a dictionary, thesauses, translations, and encyclopedia features.
Merriam-Webster.com Can use the dictionary, thesaurus, Spanish-English translator, or medical search feature by word or phrase.
Wordsmyth.net Users will need to register to use some of the features on the site; however, registering is not required to look up an exact definition.
YourDictionary.com In addition to dictionary and thesaurus features, this website provides specialized dictionaries and word games.
21 Century teaching terms dictionary