Dictionaries

Specialty and Language Dictionaries

• Foreign Language Online Dictionaries
• Grammar and Language Courses
• Specialty Dictionaries (Industry Specific Dictionaries)

Other Vocabulary Aids

Need something besides the definition of a word? A synonym or antonym? Or are you looking for an abbreviation of a phrase? Do you need your own lexical database? We have them all.

Abbreviations & Acronyms

• Search acronyms, initialisms, abbreviations on YourDictionary
• A Dictionary of Quaternary Acronyms and Abbreviations
• Abbreviations.com
• Abbreviations of Chemical Compounds (Berlin)
• Academic Journal Abbreviations
• Acronym Finder (750,000+ acronyms)
• Agriculture Acronyms
• German-English Acronym Dictionary (Berlin)
• Medical Abbreviations
• Morgan Online -  Abbreviations
• The Internet Acronym Server
• The NUMA Dictionary of Derivatives Acronyms

Antonyms, Synonyms, Homophones and Anagrams

• An English Homophone Dictionary
• Synonym Dictionary 
• Synonyms & Antonyms
• The Anagram Dictionary

Idioms and Phrases

• Search phrases and idioms on YourDictionary
• The Phrase Finder

Lexicography and Lexical Databases

• Bibliomania—Free online literature and study guide
• Electronic Text Center (browse collections by language)
• ICAME Corpus Collection
• SIGLEX (A Special Interest Group on the Lexicon by The Association for Computational Linguistics)
• The Oxford Text Archives
• Word Gumbo (Archive of public domain language resources) 
• WordNet - A Lexical Database for English

Pronunciation and Rhyming Dictionaries

• RhymZone Rhyming Dictionary and Thesaurus
• WriteExpress Online Rhyming Dictionary for Poetry and Songwriting
• Vocabulary of Alliteration

Quotations

• Search Webster's New World Dictionary of Quotations on YourDictionary
• Bartlett's Familiar Quotations (Project Bartleby)

Thesauri

• Search Webster's New World Roget's A-Z Thesaurus and Rogets II: The New Thesaurus on YourDictionary
• Roget's International Thesaurus of English Words and Phrases
• Bibliomania: "Soule's Synonymes"

Writing Systems

• Ancient Scripts.com - A Compendium of World-wide Writing Systems from Prehistory to Today
• Omniglot - Writing Systems & Languages of the World

Miscellany

• Cliché Finder
• Dictionary of Difficult Words
• GlossPost - a discussion list for translators, interpreters, terminologists and technical writers.
• Online Conversion - Over 5,000 units and 50,000 Converisons
• Bible Search

Agriculture

• Agrovoc Agricultural Database (multiple languages)

Architecture

• Architecture Topical Gloassary
• Illustrated Architecture Dictionary

Art

• ArtLex Art Dictionary
• Dictionary of Art Historians

Biography

• Search for biographies on YourDictionary

Biology

• Birdwatching Terminology
• Horse Glossary

Business

• Search business definitions on YourDictionary

Computing

• Search computer definitions on YourDictionary
• Queen Mary University of London's Language Dictionaries of Computing Terms

Construction

• Construction Dictionary and Glossary of Construction Terms

Cooking

• The Cook's Illustrated Dictionary: English, French, German, Spanish
• English to Spanish Cooking Terminology
• Multilingual Gastronomical Glossary: English, French, German, Italian, Spanish

Culture

• Search The New Dictionary of Cultural Literacy on YourDictionary

Education

• The European Education Thesaurus: Danish, German, Greek, English, Spanish, Finnish, French, Italian, Dutch, Portuguese, Swedish
• Continuing Education Glossary
• Glossary of Educational Terms

Engineering

• Electopedia: The World's Online Electrotechnical Vocabulary (multiple languages

Environment

• EPA Term of Environment: Glossaries, Abbreviations and Acronyms

Etymology

• The Tower of Babel: An International Etymological Database

Finance

• Search investment & finance definitions on YourDictionary

Fish

• Aquarium and Fish Dictionary
• Fish and Seafood Dictionary
• Online Seafood Watch Guide to Sustainable Seafood Choices

Geology

• Geoecological Dictionary (Russian to English)

Internet

• Search technical/computer definitions on YourDictionary

Law

• Search legal definitions on YourDictionary
• Canadian multilingual glossary: English, Chinese(simplified, traditional), Farsi, Punjabi, Russian, Spanish, Vietnamese

Linguistics

• Electronic Glossary of Linguistics Terms (English and Spanish)

Mathematics

• Finnish-English-Swedish Glossaries of Mathematics

Medicine

• Search medical definitions on YourDictionary

Music

• Cadenza Glossary - A Multi-lingual Dictionary of Musical Terms (English, French, German, Serbian)

Photography

• Phictionary - A Glossary of Photographic Terms (English, German, Italian, Spanish)

Religion

• Buddhism Glossary

Sailing and Shipping

• Index of Online Nautical Dictionaries

Science

• Search science definitions on YourDictionary

Telecommunications

• Terminology of Telecommunications (Arabic, Chinese, English, French, Russian, Spanish)

Textiles

• Textile Technical Dictionary (English, French, German, Spanish)
• Textile Dictionary (English, Italian, French, German)

Trade

• Foreign Trade Information System Dictionary of Trade Terms (English, Spanish, Portuguese, French)

Multilingual Dictionaries

• Index of All Language Dictionaries
• Afro-Asiatic Language Dictionaries
• Altaic Language Dictionary List
• Celtic Language Dictionaries
• Germanic Language Dictionaries
• Romance Language Dictionaries
• Slavic Language Dictionary List

General

Find phrases in French, Itaiian, German, Spanish  English German French Italian Spanish Any of these words All of these words Enter searchword(s), choose language it is written in and search type, click on 'Search'

• Allwords.com (Dutch, French, German, Italian, Spanish)
• Arabic Translator (English, French, Turkish, German)
• From Language to Language
• IATE - The EU's multilingual term base
• Slovnik.cz - Multilingual Dictionary (English, German, French, Italian, Spanish, Russian, Latin, Czech)
• The Internet Dictionary Project

Translate between Languages

• Reverso Translator (English, French, German, Spanish)
• Free Translation.Com (Arabic, English, Spanish, French, German, Italian, Portuguese plus many, many more)
• WorldLingo Text Translator (Chinese, French, German, Italian, Japanese, Korean, Portuguese, Russian, Spanish plus many, many more)

An Index of Dictionary Indices

• Encyberpedia - Dictionaries, Glossaries and Thesauri
• Kitamakura's On-line Glossary Index
• Yahoo Dictionary Index