


The American Heritage Dictionary of the English Language
This is the online version of the fourth edition of this dictionary, originally published in 2000. "Over 90,000 entries feature 10,000 new words and senses, 70,000 audio word pronunciations, 900 full-page color illustrations, language notes and word-root appendixes." Includes articles on regional patterns of American English, the Indo-European and Semitic roots of English, variation and change in our living language (how and why new words come into use), and usage notes. From Bartleby.com.
Merriam Webster Online Dictionary & Thesaurus
In addition to the classic Merriam Webster Dictionary and a Thesaurus, this site also presents a medical dictionary and a Spanish-English-Spanish word translator.
Online Dictionary Directory
The Online Dictionary Directory is a free directory of monolingual, bilingual and multilingual dictionaries, glossaries and encyclopaedias. The dictionary search currently provides links to over 100 encyclopaedias, glossaries and translation dictionaries in 137 different languages from all over the world. This online catalog is frequently updated and also enables users to add other useful encyclopaedias, glossaries and translation dictionaries that are currently not included in the Online Dictionary Directory.
Roget's II: The New Thesaurus
This well-know resource contains 35,000 synonyms and over 250,000 cross-references in an easy-to-use format. Roget's II features succinct word definitions and an innovative hyperlinked category index. From Bartleby.com.
Wordsmyth Dictionary - Thesaurus
This is an original standard dictionary-thesaurus of American English with definitions and pronunciations, an integrated thesaurus, and useage examples. Registration is required to use some features.