Dictionaries: English
Merriam-Webster OnLine The online Collegiate Dictionary is based on the print version of Merriam-Webster's Collegiate® Dictionary, Tenth Edition, and includes 1,000 illustrations.
Webster's Revised Unabridged Dictionary, 1913 Edition Sponsored by the ARTFL Project, this is the 1913 edition of Webster's Revised Unabridged Dictionary. Though it is an older edition without many technological terms, its definitions are much more complete than the 10th edition of the Merriam-Webster Online.
Oxford English Dictionary Online The Oxford English Dictionary is a great place to find the origin and historical use of words documented through literary sources.
OneLook Dictionaries A growing resource that indexes more than 3,201,707 words in over 731 different Internet dictionaries.