Quick Reference Dictionaries

General Usage/Literature & Writing Resources
Acronym and Abbreviation List: Enter an acronym and get the possible meanings. Very large, although not as; comprehensive as some print resources.
Acronym Finder: 52,000 acronyms/abbreviations and their meanings.
American Heritage® Book of English Usage: A Practical and Authoritative Guide to Contemporary English, 1996.
American Heritage Dictionary of the English Language: Unabridged, 3rd edition.
American Sign Language Browser: This site uses QuickTime so you MUST have it loaded on your machine. On the left is a list of the words that you can "view" and a movie opens in the window to show you how to make the words in ASL.
Brewer's Dictionary of Phrase & Fable: From the 1894 work of the same name; this is extensively cross-referenced, and excellent for phrases which have their roots in literature or mythology.
Cambridge International Dictionaries Online: Search the Cambridge International Dictionary of American English, Int'l Dictionary of English, Int'l Dictionary of Idioms, and Cambridges Int'l Dictionary of Phrasal Verbs.
Carnegie Mellon Pronouncing Dictionary: "The Carnegie Mellon University Pronouncing Dictionary is a machine-readable pronunciation dictionary for North American English that contains over 100,000 words and their transcriptions." (from the CMU Pronouncing Dict. website)
Devil's Dictionary: Published in 1911, Ambrose Bierce's whimsical collection of definitions.
Dictionary.com: Site includes Roget's Thesaurus, dictionary, a translator from english-to- , and various other language dictionaries.
Glossarist.com: a searchable and categorised directory of glossaries and topical dictionaries.
Index of Online Dictionaries: Huge list of online dictionaries, glossaries, etc. arranged by subject fields.
EuroDicAutom: Searches for terms in several European Languages at once.
ForeignWord: This site is full of useful utilities for translating words, definitions, and lots more.
Handspeak: A Sign Language Dictionary: Features approximately 2,800 signs and added to regularly. Visitors can use a search engine to find American Sign Language (ASL) signs for words or browse by an alphabetical index as well as by a limited subject index. Also included here are four fables told in sign language, a description of International Sign Language (ISL), and some brief, bullet-point discussions of SL culture and language. Note: the signs are demonstrated in stop-action GIF animation, so users need browsers that support this application.
Internet Public Library Word & Phrase Origins Pathfinder: Extensive directory of reference sources.
Internet Public Library Dictionaries Pathfinder: Extensive directory of online dictionaries.
Jingdagi English Reference Page: One stop shopping when you need a language reference. Includes the Merrian-Webster's Dictionary & Thesaurus, the Cambridge Dictionaries, Dictionary.Com and a Dictionary of Slang.
The King's English: by Fowler, H. W. 1908, 2nd ed.
Lexicool.com: The directory currently has links to over 500 translation dictionaries and glossaries. There are three search options. Pull-down menus give the options of specifying language-to-language search, language and subject search, or language, subject, and keyword search.
Merriam-Webster Online: Includes a dictionary, thesaurus, word-of-the-day, word game, etc.
Multilingual Dictionaries+ : from The Language Hub: The Language Hub is for translators, interpreters, scholars, travelers, or simply those with an interest in languages, present or past. It provides access to all sorts of resources on the Net: Dictionaries, Glossaries, Files, Information etc.
OneLook Dictionaries: Search 109 online dictionaries simultaneously for your term.
Online Dictionary of Library & Information Science
Online Glossaries, Dictionaries, and Encyclopedias: Includes 600+ links to glossaries, etc. on various topics. Extensive; site done by Steven Baum, Dept. of Oceanography, Texas A & M University.
Pronouncing Dictionary: Find out how to pronounce English words.
Research-It!: Interesting table-oriented index of almost every kind of online reference tool you could/would/should ever want. Includes dictionaries of several different varieties, quote finders, translators, a thesaurus, mapfinders, financial searchers, and mailing trackers.
Rhyming Dictionary: Enter your word and find perfect matches, matching last sounds, or homophones.
Roget's II Thesaurus: Provided by the folks at Bartleby.com.
Sports Glossaries: Browse or search glossaries of terms for Soccer, Ice Hockey, Football, and Basketball. Glossaries contain many cross-references.
Webster's Revised Unabridged Dictionary: From the ATRFL Project. 1913 edition.
Wilton's Etymology Page: Etymology is the study of word origins. Here you will find the origins of many colorful and interesting words and phrases. Includes a short "History of the English Language".
Xrefer: Internet meta-search engine for reference materials, including dictionaries, encyclopedias, thesaurii, more.
YourDictionary.com
Conversion Tools
A Dictionary of Units: This provides a summary of most of the units of measurement to be found in use around the world today (and a few of historical interest), together with the appropriate conversion factors needed to change them into a 'standard' unit of the S I. The units may be found either by looking under the category in which they are used [such as length, mass, density, energy etc.], or else by picking one unit from an alphabetically ordered list of units. There are NO units of currency.
ConvertIt.com: A highly useful conversion site, includes all sorts of nifty tools.
Online Conversion.com: A one stop shopping type of site with all the conversion tools you could possibly want or need.
Measuring Units Conversion Tables: site provided by "IFP", includes length, mass, area, volume/capacity, and temperature conversion machines.
Business Related
Marketing Terms.com -- Internet Marketing Reference: a dictionary and acronym glossary of internet marketing terms. Browseable by alphabetical order as well as by term or definition.
Investopedia: Searchable, database of finance and investment terms. Categories for terms include mutual funds, options and futures, retirement plans as well as acronyms, buzz words, and new economy terms. Also features the Investopedia University, a sizeable collection of tutorials and articles from the editors of Investopedia and outside sources.
InvestorWords: a glossary of over 5,000 investment terms. Browseable by alphabetical order as well as by term or definition.
Online Glossary of Research Economics: Created by Peter B. Meyer of the Economics Department at Northwestern University. Meant to be used like a dictionary: Type in your term and it will hopefully be among the Glossary's over 1,000 entries. Typing "help" into the search box will return a list of economics categories, each of which contains a directory of related terms. Terms are also browseable by alphabetical order in the "downloadable contents" section. Advice on how best to use the glossary can be found in the "How and Why of this Site" section, which also offers advice on the best way to use the glossary, and also explains some of the internal structures. Mr. Meyer sees this project as a work-in-progress and invites users to suggest entries and offer constructive feedback.
Index to Glossaries & FAQ's: Index/list of numerous business related glossaries, dictionaries, FAQ's, broken into
Marketing Encyclopedia: Index/list of marketing terminology.
Marketing Glossary: Index/list of marketing terminology. Provided by the University of Ulster Business & Management Department.
TexasAdvertising: an alphabetical glossary of advertising terms. Provided by the UT-Austin Department of Advertising.
Science Dictionaries
Glossary of Genetics Terms: Sponsored by the National Human Genome Research institute. Includes an; alphabetical list and a search function.
IUPAC Compendium of Chemical Terminology: Put together by the Royal Society of Chemistry and hosted by Chemsoc, this is a searchable online version of the "Gold Book", including over 7000 terms.
Medterms.com: Published by MedicineNet.com, this site includes over 9000 terms, abbreviations, syndromes, eponyms, and more related to the bio-medical sciences.
Merck Manual of Medical Information - Home Edition: The full-text, searchable consumer edition of the famous Merck Manual of Diagnosis and Therapy ("the textbook of medicine most widely used by health care professionals in the U.S. and worldwide"), written in everyday language for non-health care professionals.
WhoNamedIt.com: Biographical dictionary of medical eponyms, terms named for/by individuals. Includes over 5500 terms/people.
Technology Dictionaries
Dictionary of Storage Networking Technology: The members of the Storage Networking Industry Association have collaborated to create this Dictionary of Storage and Storage Networking Terminology. This dictionary thus represents the storage networking industry's most comprehensive attempt to date to arrive at a common body of terminology for the technologies it represents. Most of the terms in this dictionary have meaning primarily in specific sub-contexts of storage networking, such as SCSI or Storage Systems. Wherever this is true, the primary context(s) for the term are noted between the term itself and its definition. Terms that do not have one or more contexts identified are generally applicable data processing industry terms.
FOLDOC - Free Online Dictionary of Computing: A searchable dictionary of computing terminology, missing terms can be sent to the web-manager for inclusion within the dictionary. Provided by the Imperial College Department of Computing.
Glossary of Academic Information Technology Terms: Provided by the Rohan Academic Computing Department of SDSU.
Glossary of Digital Privacy Terms: Provided by the Privacy Foundation.
Glossary of Internet Terms: An open-content glossary of Internet terms.
Netlingo.com: The Internet Dictionary: NetLingo is an award-winning dictionary of Internet terms. It contains thousands of words and definitions that describe the online world of business, technology, and communication.
TechEncyclopedia: A searchable encyclopedia of IT terminology. Provided by TechWeb.