Agriculture and public health related glossaries compiled by various government agencies, non-profit organizations and academic sources:
Agriculture
Environmental Protection Agency - Ag101
The European Commission's Agriculture and Rural Health Glossary
Illinois Rivers Decision Support System (ILRDSS) Glossary of Agriculture Terms
National Agriculture Law Center Glossary of Agricultural Production, Programs, and Policy
New Mexico State University Agriculture Dictionary
Pennsylvania Farm Bureau Glossary of Ag Terms
Aquaculture
North Carolina Department of Fisheries
Biodiversity
European Community of Biodiversity Clearinghouse
World Resources Institute Glossary of Biodiversity
Biofuels
U.S. Dept of Energy Student Glossary of Biomass
Biotechnology
FAO Glossary of Biotechnology for Food and Agriculture
University of Vermont dictionary of Biotech terms
Climate Change
Environmental Protection Agency
Pew Center on Climate Change Glossary on Climate Change
Crops
Environmental Protection Agency
Farm Bill
USDA Economic Research Service 2002 Farm Bill Glossary
Food Safety
USDA Food Safety and Inspection Service Glossary
Food Security
FAO Global Forum on Food Security and Nutrition Policies and Strategies
Soil
Soil Science Society of America - Glossary of Soil Science Terms
Sustainable Agriculture
USDA Alternative Farming Systems Information Service - Sustainable Agriculture Definition and Terms
Water