dictionaries  general / abbreviations / acronyms / agriculture / anagrams / anthropology / arts / astronomy / aviation / biography / biology / botany / computers / education / etymology / financial / foreign language / games / genealogy / geography / grammar / history / homonyms / humanities / idioms / language / legal / literature / maritime / media / medical / military / miscellaneous / music / philosophy / politics / quotations / religion / rhymes / science / shipping / slang / social science / style / synonyms / thesaurus
 

General

• The American Heritage Dictionary of the English Language
• The Biggest Viewable Dictionary on the 'Net
• Cambridge Dictionaries Online
• Century Unabridged Dictionary (1889)
• A Concise Dictionary of Middle English
• Dictionary.com
• Dictionary of All-Consonant Words
• Dictionary of All-Vowel Words
• Dictionary of Newfoundland English
• Encarta World English Dictionary
• Funk & Wagnalls
• Google Glossary of Words, Phrases and Acronyms
• Grandiloquent Dictionary
• Information Please Almanac and Dictionary
• The Macquarie Dictionary (Australian English)
• Merriam-Webster Collegiate Dictionary
• Newbury House Dictionary of American English
• New Words in English
• OneLook Dictionaries
• Online Plain Text English Dictionary
• Phrasal Verb Page
• Webster's Dictionary (1828)
• Webster's Dictionary (1828) (christiantech.com)
• Webster's Dictionary (1913) (ucsd.edu)
• Webster's Dictionary (1913) (bibliomania.com)
• Webster's Dictionary (1913) (uchicago.edu)
• The White Queen's Dictionary of One-Letter Words
• Wordnet: A Lexical Database for the English Language
• WordNet Vocabulary Helper
• Wordsmyth: The Educational Dictionary-Thesaurus

Abbreviations

• Three Letter Abbreviations 

Acronyms

• Acronym & Abbreviation Server 

• Acronym Finder 

• Opaui Guide 

Agriculture

• GFL (Berkeley)
• Lynda Birch (Australian agriculture department)
• Rice 

Anagrams

• Anagrams Dictionary 

Anthropology

• Anthropology Glossary 

Arts

• An Illustrated Dictionary of Jewelry
• Animation Art Glossary
• ArtLex Art Dictionary
• Ballet Dictionary (American Ballet Theatre)
• Banjo Glossary
• Book Collectors Glossary
• David's Glossary of Theatre Terms
• Dictionary of Art Terms
• Dictionary of Dance
• Glossary of Poetic Terms (Robert G. Shubinski)
• Glossary of Poetic Terms (Ian Lancashire)
• Glossary of Technical Theatre Terms
• Movie Terminology Glossary
• Textile Technical Dictionary
• Words of Art

Astronomy

• Space/Astronomy

Aviation

• AOPA

• Honeywell 

Biography

• Biographical Dictionary
• Biographical Dictionary of English Literature
• Biographies of Composers
• Biography.com

• Mathematical Biographies

• Science Fiction Writers

Biology

• Biodiversity
• Biotech
• Zoology Glossary 

Botany

• Botany Dictionary
• Botany Encyclopedia
• USDA Plants Database
• Virtual Garden

Business

• ABC News Business Glossary
• Advertising Terminology
• Bloomberg Financial Glossary
• E-Commerce and Marketing Dictionary of Terms
• English-Spanish Business Glossary
• Trading Glossary

Computers

• Babel Acronyms

• Barkley's Comprehensive Technical Glossary

• Emoticons

• Foldoc Computing

• Free On-Line Dictionary of Computing

• Hacker Dictionary

• The Jargon File

• Netdictionary

• Ultimate 

Education

• Education Glossary

Etymology

• Etymologically Speaking

• Etymology: The Science of Word Histories

• German English Words

• Hobson Jobson Dictionary of Anglo/Indian Words (1902)
• Word Origins
• World Wide Words

Financial

• AICPA

• Barkley's Comprehensive Financial Glossary

• Currency Codes

• Derivatives Dictionary

• Global Investor Glossary

• Glossary of Credit Terms

• Glossary of Futures and Options Terminology

• Guide to Futures and Options Market Terminology

• Guide to Securities Terminology

• Investing Terms You Should Know

• Investopedia

• Yahoo Financial Glossary

Foreign Language

• Babel Fish : Translation service from AltaVista.  Translate any word, text or web page to or from English from French, German, Italian, Portuguese, Russian and Spanish.

• LOGOS Dictionary
   
• Afrikaans (travlang.com)

• Afrikaans (freedict.com)

• British English

• Bhuddist
• Czech
• Danish (travlang.com)

• Danish (freedict.com)

• Dutch (freedict.com)

• Dutch (travlang.com)
• Esperanto (travlang.com)

• Esperanto

• Estonian

• Faclair Gàidhlig (Scots Gaelic)

• Finnish (ttravlang.com)

• Finnish (freedict.com)

• Fockleyr Gaelg (Gaelic)

• French (Univ. of Chicago)

• French (freedict.com)

• French (travlang.com)
• Frisian
• German (travlang.com)

• German (leo.org)

• Gilbertese (Kiribati)

• Greek

• Hebrew

• Hmong (Cambodian)

• Hungarian (freedict.com)

• Hungarian (travlang.com)

• Indonesian

• Indonesian (freedict.com)

• Italian

• Italian (freedict.com)

• Italian (travlang.com)

• Japanese

• Latin

• Latin (freedict.com)

• Latin (travlang.com)

• New Zealand English

• Norwegian (freedict.com)

• Norwegian (travlang.com)
• Portuguese (travlang.com)

• Portuguese (freedict.com)

• Punjabi

• Russian

• Serbian

• Spanish (efn.org)

• Spanish (freedict.com)

• Spanish (travlang.com)

• Sudovian (Baltic)

• Swahili (freedict.com)

• Swahili (yale.edu)
• Swedish (travlang.com)

• Swedish

• Swedish (freedict.com)

• Taino (Native American)

• Tarawan 

Games

• Miniature Wargaming Glossary

Geneaology

• Genealogy Dictionary
• Glossary of Diseases
• Legal Terms in Land Records
• Old Medical Terminology 
• Tombstone Initials and Their Meanings (Obit Central)

Geography

• AGI Geographic

• Dictionary of Abbreviations and Acronyms in Geographic Information Systems, Cartography and Remote Sensing (U.C. Berkeley)
• Geographic Information Service Dictionary (AGI)

• Getty Geographic Thesaurus

Grammar

• Guide to Grammar and Writing
• Hutchinson Dictionary of English Usage
• The Internet Grammar of English
• The Online English Grammar

History

• Global Glossary (Greco-Roman)
• Medieval : Glossary of medieval terminology.

Homonyms

• Alan Cooper's Homonyms
• An English Homophone Dictionary

Humanities

• In Other Words : A Lexicon of the Humanities.

Idioms

• ESL Idiom Page
• GoEnglish.com Idiom Dictionary

Language

• A Basic Guide to Americal Sign Language Terms

Legal

• Annotated Divorce Law Dictionary

• Blue Book of Legal Citation (16th ed.)

• Dictionary of Canadian Bankruptcy Terms

• A Dictionary of Law

• Divorce Dictionary

• Duhaime's Law Dictionary

• Everybody's Law Dictionary

• Findlaw Dictionary

• Insurance Company Listing

• Martindale Hubble Lawyer Locator

• Nolo Legal Dictionary 

• Oran's Dictionary of the Law

Literature

• An Etymological Dictionary of Classical Mythology
• A Faulkner Glossary
• A Glossary of Literary Terms
• Index from the Encyclopedia Mythica
• An SF (Science Fiction) Glossary
• Shakespearean Glossary

Maritime

• AMSA 
• Cargo Shipping Acronyms
• The Mariner's Jewel (1735)
• The Sea-Man's Vade Mecum (1707)
• The Ship-Builder's Assistant (1711, 1740)
• Shipping Abbreviations

Media

• Broadcast Terminology

Medical

• AMA Medical
• Austrailian
• Medterms
• On-line Medical Dictionary
• Vision Dictionary

Military

• DOD Military
• DOD Dictionary 

Miscellaneous

• Death and Funeral Glossary

Music

• Creative Music Online Dictionary of Musical Terms
• A Folkie's Dictionary (Folk music)
• Glossary of Electronic Music Terms
• Glossary of Music
• Glossary of Musical Instruments
• Glossary of Recording Terms
• Glossary of the Latin Beat
• Index of Musical Instruments
• Liber Organum: An Organ Glossary of Stop Names
• The Official Band Dictionary
• Operas and Composers: A Pronunciation Guide

Philosophy

• Dictionary of Philosophy of Mind
• A Dictionary of Philosophical Terms and Names
• Dictionary of Sensibility
• Dictionary of Symbolism
• Ethics Glossary
• Glossary of Terms in Eastern Philosophy

Politics

• French-Russian Glossary of UNESCO Terminology

Quotations

• Adam Fuegi's Collected Quotations
• Advertising Quotes
• Ariga Glossary of Yiddish Expressions
• Bartlett's Familiar Quotations (1919) (bartleby.com)
• Bartlett's Familiar Quotations (columbia.edu)
• Brewer's Dictionary of Phrase and Fable (1898) (bartleby.com)
• Brewer's Dictionary of Phrase and Fable (1898) (bibliomania.com)
• The Columbia World of Quotations (1996)
• Creative Quotations
• A Dictionary of Scientific Quotations
• Famous Quotes Page
• Figures of Speech
• Grocott's Quotations
• List of Yiddish Words and Expressions
• The Phrase Finder
• Quotable Quotes
• Quotations Home Page
• The Readers Handbook
• A Short Dictionary of Scientific Quotations
• Sayings and Everyday Expressions
• Simpson's Contemporary Quotations (1988)
• Ye Olde English Sayings

Religion

• Concise Dictionary of Religion

Rhymes

• Lycos Rhyming Dictionary 
• RhymeZone: Rhyming Dictionary and Thesaurus

Science

• BioTech Life Science Dictionary
• Biotechnology
• Chemical Compounds
• Dictionary of Units
• Glossary of Neclear Terms
• Nuclear Glossary 
• ODLIS: Online Dictionary of Library and Information Science

Slang

• 1960's Slang
• The Alternative Dictionaries
• American-Australian Slang Dictionary
• American Slanguages
• The Cavers Slang Dictionary
• Drug-Related Street Terms/Slang Words
• Dublin Slang Dictionary and Phrasebook
• English Slang and Colloquialisms Used in the United Kingdom
• A Glossary of the Low Life
• Jargon Dictionary
• The Jargon Dictionary
• Jazz Slang
• Larry's Aussie Slang and Phrase Dictionary
• Macquerie Dictionary of Slang (Australian)
• A Prisoner's Dictionary
• The Rap Dictionary
• A Seattle Lexicon
• Surfer Slang
• Twists, Slugs and Roscoes: A Glossary of Hardboiled Slang

Social Science

• Dictionary of Occupational Titles
• Dictionary of Sexology
• Glossary of Social Science Computer and Social Science Data Terms
• A Glossary of the Humanities

Style

• American Heritage Book of English Usage (1996)
• The American Language (1921) (H.L. Mencken)
• Brewer's Readers Guide (1898)
• The Columbia Guide to Standard American English (1993)
• The Elements of Style (1918)
• Glossary of Linguistic Terms
• A Glossary of Rhetorical Terms
• A Handbook of Rhetorical Style
• The King's English (1908)
• On the Art of Writing (1916)

Synonyms

• The A to Z of Alternative Words
• A Dictionary of English Synonymes and Synonymous or Parallel Expressions (1871)
• Soule's Synonyms
• Synonyms Dictionary

Thesaurus

• Merriam-Webster Collegiate Thesaurus
• Roget's II: The New Thesaurus (3rd ed.; 1995)
• Roget's International Thesaurus of English Words and Phrases (1922)
• Roget's Thesaurus (1930)
• Thesaurus.com
• Wordsmyth: The Educational Dictionary-Thesaurus