Chemical Safety Information - Glossary
A resource developed by the Physical and Theoretical Chemistry Laboratory at Oxford University. The resource comprises a clickable alphabetical list of terms related to chemical safety and hazardous materials. Each term is concisely defined and explained.
http://ptcl.chem.ox.ac.uk/MSDS/glossary/GLOSSARY.html

Dictionary of Inorganic and Organometallic Compounds
This dictionary provides extensive properties information for over 100,000 inorganic, organometallic, and coordination compounds. This is part of the CHEMNetBASE collection of chemistry databases.
http://www.chemnetbase.com/scripts/diocweb.exe

Electrochemistry Dictionary
Simple and brief definitions of words and phrases used often in electrochemistry. In some cases, a second paragraph provides further information for the "more scientifically minded."
http://electrochem.cwru.edu/ed/dict.htm

General Chemistry Glossary
A searchable, crosslinked collection of over 1000 chemical terms and abbreviation with audio pronunciations. Part of General Chemistry Online by Fred Senese at Frostburg State University.
http://antoine.frostburg.edu/chem/senese/101/glossary.shtml

Glossary of Archaic Chemical Terms
This glossary was developed based on terms that the author came across in the course of reading classic chemistry papers. It has been expanded to include formulas and structures for some common acid-base indicators and vitamins, as well as some other interesting non-systematic chemical terms.
http://web.lemoyne.edu/~giunta/archema.html

Glossary of HPLC Terms
An online glossary of terms used in high performance liquid chromatography (HPLC), compiled by the Waters Corporation. Approximately 200 definitions are provided in an alphabetical browse list.
http://www.waters.com/WatersDivision/ContentD.asp?watersit=EGOO-66ESN3

UNCChem Glossary
This glossary contains fundamental terms of chemistry that would be used in freshman level chemistry classes. Click on the first letter of the term to find the word you want to look up.
http://www.shodor.org/UNChem/glossary.html