a combining form meaning “the earth,” used in the formation of compound words: geochemistry.

Nearby words

  1. genupectoral position,
  2. genus,
  3. genève,
  4. genêt,
  5. geo,
  6. geo-economics,
  7. geo.,
  8. geobotany,
  9. geocaching,
  10. geocarpy

Origin of geo-

< Greek geō-, combining form of the earth

Geo. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for geo

British Dictionary definitions for geo



/ (ˈdʒiːəʊ) /

noun plural geos or gios

(esp in Shetland) a small fjord or gully

Word Origin for geo

C18: from Old Norse gjā ravine; related to Old English gionian to yawn


combining form

indicating earthgeomorphology

Word Origin for geo-

from Greek, from earth

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

Word Origin and History for geo


word-forming element meaning "earth," ultimately from Greek geo-, comb. form of ge "earth" (see Gaia).

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for geo




The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for geo



A prefix that means “earth,” as in geochemistry, the study of the Earth's chemistry.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.