Acronyms

• Acronym Finder

Biographies

• Biographical Dictionary
• Biography.com

Biology

• Life Science Dictionary . BioTech . Indiana University

General

• AllWords.com
• AnsMe.com
• BrainyDictionary
• Cambridge Dictionaries
• Dictionary.com
• HyperDictionary.com
• Longman
• Merriam-Webster
• OneLook
• Real Dictionary
• Roget's Thesaurus
• TheFreeDictionary.com
• Thesaurus.com
• Wikcionário
• Wordsmyth
• YourDictionary.com
• YourThesaurus

Informatics and Internet

• FOLDOC
• NetLingo
• Webopedia

Logic

• Critical Thinking Glossary . Lauren Miller
• Glossary of First-Order Logic . Peter Suber
• Logic Glossary . Mary Haight
• Logic Glossary . Michael Eldridge

Measures

• Measures, Units and Conversions . Frank Tapson
• Units of Measurement . Russ Rowlett

Multilingual

• EuroDicAutom
• Language Center . Jim Martindale
• Lexicon: Greek-English-Greek Dictionary

Philosophy

• Dictionary of Sensibility . Corey Brady et al
• Skeptic's Dictionary . Robert T. Carroll
• The Ism Book . Peter Saint-André
• Dicionário de Filosofia . A. R. Gomes
• A Arte de Pensar . Didáctica Editora
• Buddhist Glossary . Paul Trafford
• Cognitive Science Dictionary . University of Alberta
• Dictionary of Islamic philosophical terms
• Dictionary of Philosophical Terms and Names . Garth Kemerling
• Dictionary of Philosophy of Mind . Chris Eliasmith
• Digital Dictionary of Buddhism . Charles Muller
• Factasia Glossary . Roger Bishop Jones
• Free On-Line Dictionary of Philosophy . SWIF
• Glossary of Hegelian Terms . Andy Blunden
• Glossary of Kant's Technical Terms . Stephen Palmquist
• Glossary of Leibniz's Monadology . Roger Jones
• Glossary of Philosophical Terms . Nicholas Bunnin . E. P. Tsui-James
• Glossary of Religious Terms . B.A. Robinson
• Glossary of Sanskrit Terms in Integral Yoga Literature
• Internet Encyclopedia of Philosophy . James Fieser
• Kant Lexicon . G. J. Mattey
• Lexicon of Foreign Words in Philosophy Texts
• Mostly Modern Philosophical Glossary . Larry Hauser
• Philosophical Glossary . Justin Leiber
• Philosophy of Mind Glossary . Darren Brierton
• Philosophical Dictionary . Garth Kemerling

Politically Incorrect

• Devil's Dictionary . Ambrose Bierce

Portuguese

• Dicionários Porto Editora
• Dicionário Universal da Língua Portuguesa
• Meus Dicionários
• Priberam

Slangs

• English Slang . UK

Skepticism

• Skeptic's Dictionary . Robert T. Carroll

Structured

• EASG Conceptual Dictionary . Frederick Clifford Gibson

Acrônimos

• Acronym Finder

Astronomia

• Dicionário de Astronomia e Áreas Afins . Centro de Estudos Astronômicos de Alagoas

Biografias

• Biography.com
• Biographical Dictionary

Biologia

• Dicionário de Aves
• Life Science Dictionary . BioTech . Indiana University

Ceticismo

• Skeptic's Dictionary . Robert T. Carroll
• Dicionário do Cético . Robert T. Carroll

Estruturados

• EASG Conceptual Dictionary . Frederick Clifford Gibson

Filosofia

• Dictionary of Sensibility . Corey Brady et al
• Skeptic's Dictionary . Robert T. Carroll
• The Ism Book . Peter Saint-André
• Dicionário de Filosofia . A. R. Gomes
• A Arte de Pensar . Didáctica Editora
• Buddhist Glossary . Paul Trafford
• Cognitive Science Dictionary . University of Alberta
• Dictionary of Islamic philosophical terms
• Dictionary of Philosophical Terms and Names . Garth Kemerling
• Dictionary of Philosophy of Mind . Chris Eliasmith
• Digital Dictionary of Buddhism . Charles Muller
• Factasia Glossary . Roger Bishop Jones
• Free On-Line Dictionary of Philosophy . SWIF
• Glossary of Hegelian Terms . Andy Blunden
• Glossary of Kant's Technical Terms . Stephen Palmquist
• Glossary of Leibniz's Monadology . Roger Jones
• Glossary of Philosophical Terms . Nicholas Bunnin . E. P. Tsui-James
• Glossary of Religious Terms . B.A. Robinson
• Glossary of Sanskrit Terms in Integral Yoga Literature
• Internet Encyclopedia of Philosophy . James Fieser
• Kant Lexicon . G. J. Mattey
• Lexicon of Foreign Words in Philosophy Texts
• Mostly Modern Philosophical Glossary . Larry Hauser
• Philosophical Glossary . Justin Leiber
• Philosophy of Mind Glossary . Darren Brierton
• Philosophical Dictionary . Garth Kemerling

Gerais

• Wikcionário
• YourThesaurus
• Roget's Thesaurus
• Thesaurus.com
• TheFreeDictionary.com
• YourDictionary.com
• Wordsmyth
• Real Dictionary
• OneLook
• Merriam-Webster
• Longman
• HyperDictionary.com
• Dictionary.com
• Cambridge Dictionaries
• BrainyDictionary
• AnsMe.com
• AllWords.com

Gírias

• English Slang . UK

Informática e Internet

• NetLingo
• Webopedia
• FOLDOC

Lógica

• Critical Thinking Glossary . Lauren Miller
• Logic Glossary . Michael Eldridge
• Logic Glossary . Mary Haight
• Glossary of First-Order Logic . Peter Suber

Medidas

• Measures, Units and Conversions . Frank Tapson
• Units of Measurement . Russ Rowlett

Meio Ambiente

• Dicionário do Ambiente . Jornal do Meio Ambiente . Vilmar Berna

Meteorologia

• Glossário Meteorológico . Weather Channel

Multilíngües

• Lexicon: Greek-English-Greek Dictionary
• Meus Dicionários
• Language Center . Jim Martindale
• EuroDicAutom

Politicamente Incorretos

• Devil's Dictionary . Ambrose Bierce

Português

• Dicionários Porto Editora
• Dicionário Universal da Língua Portuguesa
• Meus Dicionários
• Priberam

Psiquiatria

• PsiqWeb . Sociedade Paulista de Psiquiatria Clínica

Química

• Dicionário de Química . Rossetti

Sinais

• Dicionário Libras