Dictionaries: English

American Heritage Dictionary  Available for free on the Internet, this dictionary contains over 90,000 entries with 70,000 audio word pronunciations, plus 900 full-page color illustrations, language notes and word-root appendixes.  Includes Roget’s Thesaurus, Dictionary of Cultural Literacy, and Word of the Day feature.

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.

OneLook Dictionaries  A growing resource that indexes more than 3,201,707 words in over 731 different Internet dictionaries.

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 WWWebster Dictionary.