Mainly English Language, Some Multilingual
How Stuff Works
Explains hundreds of subjects, from car engines to lock-picking to ESP, using clear language and tons of illustrations.
Computers / Information Technology
Free AutoCAD tutorials in English to help you familiarize yourself with CAD terminology and concepts. Ranging from general to extremely detailed. Click the AutoCAD FAQ tab to access link to glossary and knowledgebase.
Free Online Dictionary of Computing.
Microsoft Language Portal
You can search Microsoft's localization glossaries and terminology database for terms and phrases in over 90 languages and download style guides. Essential when you need equivalent terms in other languages for user interface entries and messages of Microsoft products, and for computer translation generally.
"The only online dictionary and search engine you need for computer and Internet technology definitions."
Electrical Engineering / Electronics
Produced by the IEC, Electropedia is the world's leading online electrical and electronic database containing more than 20,000 terms and definitions in English and French organized by subject area, with equivalent terms in Arabic, Chinese, German, Italian, Japanese, Portuguese, Polish, Russian, Spanish and Swedish (coverage varies by subject area).
Glossary of energy terms and definitions used in EIA data, reports, presentations, and survey forms from the U.S. Energy Information Administration. Also includes a list of abbreviations The site also has an Energy Basics 101 page with simple, illustrated explanations of many topics related to all types of energy and the energy industry.
Glossary of Biomass Terms
English-only glossary from the Natural Renewable Energy Laboratory.
Language of the Nucleus
Glossary of 100,000 nuclear science, engineering, medicine and national security terms. Includes largest collection of terms available on radiation, radioactivity and nuclear energy. English only, from Scientific Digital Visions, Inc.
Nuclear Energy Glossary
English-language glossary from the United States Nuclear Regulatory Commission. Site also has lots of information on nuclear reactors, nuclear materials, radioactive waste, etc.
U.S. Department of Energy: Energy Efficiency and Renewable Energy
Lots of information in English on renewable energy sources with a number of English glossaries.
“An apparel industry directory providing members of the fashion industry with links to virtually every aspect of apparel, fashion, textiles, and clothing.” Of particular interest are the many different extensive lists of definitions related to all the categories mentioned above (English only).
How Products Are Made
Excellent site (once you get past the Google ads) that explains and details the manufacturing process of a wide variety of products, from daily household items to complicated electronic equipment and heavy machinery. Also tells how they work, their history, raw materials,possible future developments, quality control procedures, etc.
TEDDI (TErms and Definitions Database Interactive)
Terminology from ETSI (European Telecommunications Standards Institute) standards, specifications and reports, all related to the telecommunications industry.
TERMITE Telecommunication Terminology Database
Database of the International Telecommunication Union (ITU) with terminology in English, French, Spanish, Arabic, Chinese and Russian.
Comprehensive directory of Aviation glossaries and Aviation dictionaries that contain aeronautical terms, terminology and photos.
Dictionary of Automotive Terms
An illustrated, English-language glossary of over 20,000 terms for automobiles, bicycles, motorcycles, engines, and boats.
Very detailed English-language dictionary of maritime terms with frequent updates from contributors worldwide. Provided by Asia's Maritime Industry online.
Modern Railway TerminologyVery specialized, illustrated English-language glossary of railway terms, covering modern systems and steam locomotives and including a comparative glossary of US-UK terminology from Railway Technical Web Pages.