[ jee-ol-uh-jee ]
See synonyms for geology on
noun,plural ge·ol·o·gies.
  1. the science that deals with the dynamics and physical history of the earth, the rocks of which it is composed, and the physical, chemical, and biological changes that the earth has undergone or is undergoing.

  2. the study of this science.

  1. the geologic features and processes occurring in a given region on the earth or on a celestial body: the geology of Mars; the geology of eastern Kentucky.

Origin of geology

First recorded in 1680–90; geo- + -logy

Words Nearby geology Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use geology in a sentence

British Dictionary definitions for geology


/ (dʒɪˈɒlədʒɪ) /

  1. the scientific study of the origin, history, structure, and composition of the earth

  2. the geological features of a district or country

Derived forms of geology

  • geological (ˌdʒɪəˈlɒdʒɪkəl) or geologic, adjective
  • geologically, adverb
  • geologist or geologer, noun

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for geology


[ jē-ŏlə-jē ]

  1. The scientific study of the origin of the Earth along with its rocks, minerals, land forms, and life forms, and of the processes that have affected them over the course of the Earth's history.

  2. The structure of a specific region of the Earth, including its rocks, soils, mountains, fossils, and other features.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for geology


The science devoted to the study of the Earth, particularly the solid Earth and the rocks that compose it.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.