Dictionaries, Thesauri, & Encyclopedias on the Web
This Web page has links to multiple online dictionaries, thesauri, and encyclopedias--there are even more out there. Some of the sites listed here have more than one of these reference tools, and some are listed under more than one category. It is recommended that you look up your term(s) on more than one site. As with all resources, let the user beware. If something doesn't look accurate, check additional (including print) sources.
Dictionaries
Look up definitions of words.
Single Titles
American Heritage Dictionary of the English Language. 4th edition, 2000. Subset of Bartelby.com.
Dictionary.com. Lexico LLC.
Multiple Links
Answers.com™ Reference. Copyright © 2006 Answers Corporation. All rights reserved.
Not really a straightforward dictionary, but supplies definitions. Mulitiple types of reference resources, including encyclopedias.
Dictionaries. Librarian's Index to the Internet.
Dictionaries. LibrarySpot.com
Includes links to Special (Business/Finance, Etymology, Humanities, Legal, Medical, Professional, Rhyming, Science, and Technology) and Foreign Language Dictionaries (Chinese, French, German, Italian, Japanese, Spanish).
Dictionaries, Encyclopedias & Almanacs. Rutgers University.
Dictionaries Resources. Internet Public Library.
Dictionaries/Languages. Galileo, University System of Georgia.
Freeality Online Dictionaries.
Online Medical & Science Dictionaries. MedBioWorld.
Dictionary Collections, Life Science Dictionaries and Glossaries, Medical Dictionaries, Online Chemistry Dictionaries, Other Science Dictionaries, and Multilingual Dictionaries.
yourDictionary.com. yourDictionary.com Inc.
Over 1800 online dictionaries (more than 250 languages), including specialized, language, multi-lingual, translation, and thesauri, grammers, and more.
Thesauri
Find synonyms for words you already know. Most of these are Roget's, but on different searching platforms.
Roget's Thesaurus. Bartleby.com.
RhymeZone. Datamuse and Lycos, Inc.
Thesauri. LibrarySpot.
Thesauri. yourdictionary.com.
Thesaurus.com. Lexico LLC.
Encyclopedias
Get background information for your research. For descriptions of these encyclopedias, see General Encyclopedias, which also lists print encyclopedias.
Columbia Encyclopedia. Sixth Edition. Bartleby.com
Infoplease.com. Columbia Encyclopedia, Fifth edition (1993).
Encarta Free Encyclopedia. Microsoft.
Electric Library. Infonautics Corporation.
Foreign Language Dictionaries
These sources offer dictionaries for foreign languages, English-foreign, and foreign-English dictionaries. As with printed language to language dictionaries, these are only going to be as reliable as you are familiar with the language in question.
Dictionaries. Heikki Kantola.
Foreign Language Dictionaries. LibrarySpot.
foreignword.com. foreignword.com.
Glossaries by Language. Language Automation, Inc.
Language Dictionaries. yourDictionary.
Language Dictionaries and Translators. Bigben.
Grammar
Grammar Girl's Quick and Dirty Tips for Better Writing (text and podcasts). Copyright Mignon Fogarty, Inc.
Content: Naomi Lederer; many links suggested by Dorothy Leising