Geography

About.com: Geography Glossary
Geographical terms defined.
http://geography.about.com/education/scilife/geography/library/misc/blgg.htm

Biogeography Glossary
Terms arranged according to various subject categories including general biogeography, ecology, evolution, landscape ecology and taxonomy maintained by Radford University.
http://www.runet.edu/~swoodwar/CLASSES/GEOG235/glossary.html

Free Edition of the AGI GIS Dictionary
Nearly 1,000 GIS terms and 52 diagrams published by the Association for Geographic Information and the University of Edinburgh Department of Geography.
http://www.geo.ed.ac.uk/agidict/welcome.html

Geographic.org: Glossary
Alphabetized list of words with definitions.
http://www.geographic.org/glossary.html