Science

Dyer Labs Technical Resource Glossaries
Specialized multi-language technical glossaries for optical microscopy, firearms and a general glossary of abbreviations.
http://www.dyerlabs.com/glossary/

FDA Pesticide Glossary
Glossary of alternative names for pesticides and related chemicals in PDF format.
http://vm.cfsan.fda.gov/~frf/pestglos.html

Food Resource Glossary
A source of science-based and business savvy information for the food industry.
http://food.oregonstate.edu/glossary/index.html

A Glossary of Color Science
Organized by Alex Byrne and David Hilbert.
http://tigger.uic.edu/~hilbert/Glossary.html

Linguistic Glossary
This is a glossary of terms used in the morphological, syntactic, and pragmatic analysis of text.
http://www.sil.org/linguistics/GlossaryOfLinguisticTerms/

Metallurgical Dictionary
Searchable dictionary of more than 1,000 metallurgical terms.
http://www.principalmetals.com/glossary/step1.asp

Oil and Gas Well Drilling Glossary
Comprehensive and illustrated glossary provided by Petex and the University of Texas Austin.
http://www.osha.gov/SLTC/etools/oilandgas/glossary_of_terms/glossary_of_terms_c.html

Stammtisch Beau Fleuve
Glossary of 2,000 science and technology related terms with a healthy mix of other hard-to-categorize references.
http://www.plexoft.com/SBF/