The American Geosciences Institute (AGI) Glossary of Geology is a reference vocabulary for the earth sciences. Information includes terms and definitions together with term history; the meaning of abbreviations, prefixes and acronyms common in the geoscience vocabulary; the dates many terms were first used; the preferred term of two or more synonyms; and in some cases a syllabification guide and background information. The Glossary is available in print, e-book or via online subscription. Online subscriptions are available for institutions only, and not to individuals.