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A Web of On-line Dictionaries - dictionary and thesaurus of the English language. By Merriam-Webster. Based on Merriam-Webster's Collegiate(R) Dictionary, 10th Ed.

AP Dictionary of Science and Technology - the largest scientific dictionary ever compiled in the English language to the Web. Search from over 130,000 terms defined in 130 fields of science. By Harcourt and Academic Press.

Bio Tech Life Science Dictionary - has 8300+ terms deal with biochemistry, biotechnology, botany, cell biology and genetics. This free resource was developed by the staff members at BioTech.

A Hypermedia Glossary of Genetic Terms - a well organized glossary with 600+ terms. By plant breeder and horticulturist Dr. Birgid Schlindwein.

List of Dictionaries - the complete dictionary and glossary list included in the famous OneLook Dictionaries word search database. Includes 16 pertaining to religion and 78 pertaining to science at last count. By Robert K Ware.

UCMP Glossary - a multi-volume, multimedia virtual glossary of biological terms from the University of California-Berkeley's Museum of Paleontology.

Dictionary of Philosophy of Mind - a free resource to all those interested in the philosophy of mind. By Chris Eliasmith (Ed.).

Philosophy Terms and Definitions - from the web site Philosophy for Everyone. By Ryan Breedon.

Dictionary of Philosophy - a concise guide to technical terms and personal names often encountered in the study of philosophy. By Garth Kemerling.

Reference Desk - consists of links to glossaries or dictionaries from several scientific disciplines.  They are provided and maintained by government, academic, research-oriented, and professional organizations.

Dictionary/Thesaurus - by Go.com and Interactive Learning Network (ILN).

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The Oxford English Dictionary – The largest and most authoritative dictionary of the English Language and the ultimate source of information of the usage and meaning of English words and phrases. Found in most public libraries.