Ready Reference: Dictionaries & Thesauri

Oxford English Dictionary: Online version of the print dictionary.
ARTFL Project: Webster's Revised Unabridged Dictionary, 1913 Edition: Searchable Webster's Dictionary with embedded hypertext links from the American and French Research on the Treasury of the French Language Project at the University of Chicago.
Hypertext Webster Gateway: Provides a point-and-click client interface for accessing various dictionary services on the Internet.
OneLook Dictionaries: Search the OneLook Dictionary indexes for the word you seek; if no match is found in the dictionaries selected, then the other dictionaries are searched.
WWWebster Dictionary: The World Wide Web edition of Merriam-Webster's Collegiate Dictionary, Tenth Edition.
Wordsmyth: The Educational Dictionary-Thesaurus: An easy-to-use word tool that combines the functions of a dictionary and thesaurus.

Chinese Character Genealogy Dictionary
English-Esperanto and Esperanto-English Dictionaries
German-English On-line Dictionary
Ethnologue: Catalog of more than 6,700 languages spoken in 228 countries; includes over 39,000 language names, dialect names, and alternate names.
iLoveLanguages: A comprehensive catalog of language-related Internet resources. Includes online language lessons, translating dictionaries, programs to aid you in learning a language, and more.
The Internet Dictionary Project: Allows you to translate English words into other languages or vice-versa. The IDP currently has searchable French, German, Italian, Portuguese, and Spanish dictionaries.
The LOGOS Dictionary: Freely-accessible database with over seven million entries corrected online by a network of professional translators.
Online Language Dictionaries and Translators: Large selection of language dictionaries.
YourDictionary.com: A portal for language and language-related products with over 1800 dictionaries.

Baker's Student Encyclopedia of Music: Cross-referenced entries, illustrations, and interesting sidebar facts and anecdotes.
The Biographical Dictionary: Contains information on over 19,000 notable people from ancient times to the present.
Free On-Line Dictionary of Computing: FOLDOC is a searchable dictionary of acronyms, jargon, programming languages, tools, architecture, in fact anything to do with computing.
ILC Glossary of Internet Terms: Find out what all those Internet acronyms mean--from Internet Literacy Consultants.
NetLingo: Award-winning dictionary of Internet terms.
The On-Line Medical Dictionary: Created by Dr. Graham Dark, it contains terms relating to biochemistry, cell biology, chemistry, medicine, molecular biology, physics, plant biology, radiobiology, science and technology. This edition is distributed by CancerWEB under licence from Academic Medical Publishing.
A Semantic Rhyming Dictionary: Find words that rhyme with, almost rhyme with, or sound exactly the same as a certain target word.
The Visual Dictionary: Offers annotated images with identification of parts and elements.

Plumb Design Visual Thesaurus: This unique thesaurus presents synonyms graphically. Enter a word in the search box and synonyms will radiate from the original term in a unique visual display of language. The Visual Thesaurus contains over 50,000 words and 40,000 phrases.
Roget's II: The New Thesaurus: Provides over 35,000 synonyms from the 1995 edition. Contains succinct definitions as well as synonyms
Thesaurus.com: A catalog of English words and phrases that can be accessed by keyword searching, alphabetical list, or browsing an outline which groups words by similarity of meaning.
WWWebster Thesaurus: World Wide Web version of thesaurus from Merriam-Webster.

Acronym Server: This is the list of acronyms and abbreviations in the Network Acronym and Abbreviation Server at University College, Cork.