• Aquatic, Wetland and Invasive Plant Glossary - a good resource from the University of Florida.
• Arctic Wildlife Glossary - a brief list of terms, offered by the Smithsonian Institute.
• Biodiversity Glossary of Terms - a good list of terms from the World Resources Institute, with some helpful cross-references.
• Bird Dictionary - great resource for bird-watchers!
• Energy - Glossary of Terms - from the Northeast Energy Commerce Association.
• Environmental Business Communications Glossary - offered by EuGeos, an UK-based environmental consulting firm.
• Environmental Contaminants Encyclopedia - compiled by the National Park Service with assistance from Colorado State University.
• Entomological Glossary - offered by Coleoptera.com.
• The GIS Dictionary - offered by the University of Edinburgh, Department of Geography.
• Glossary of Avian Terms - for use in Avian Conservation Biology, offered by the United States Geological Survey.
• Glossary of Marine Biology - from the State University of New York.
• Insectlopedia  - Includes a database of insects.
• Plant Dictionary - from Ohio State University.
• Plant Pathology - Technical Terms - from Cornell University.
• Wildlife Terms - from North Carolina State University.

Glossary Links

• Environmentally-Related Terminology - a series of glossaries provided by the US EPA, as listed on The Environmental Site
• Internet Resource Guide for Zoology - more than just zoology, this site offers a huge list of links to environmental, discipline-specific glossaries and dictionaries.

General Glossaries

• Compendium of Environmental Acrnoyms - a great resource for figuring out what all of those acronyms stand for!
• Environmental Glossary - adapted from "Reporting on the Environment: A Handbook for Journalists," by Sharon M. Friedman and Kenneth A. Friedman
• EPA's Terms of the Environment - defines in non-technical language the more commonly used environmental terms appearing in EPA publications, news releases, and other Agency documents available to the general public, students, the media, and Agency employees
• Multilingual Environmental Glossary - offered by the European Environment Agency.

Searchable Database

• SOLUTIONS Software Corp. Environmental Glossary Search  - over 4,000 Chemical, Environmental, and Regulatory Terms, Acronyms, Definitions, and Trade Names