geo-

¹

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

   geochemistry.

Geo.

²

abbreviation

1. George.

geo

¹

/ ˈdʒiːəʊ /

noun

1. (esp in Shetland) a small fjord or gully

geo-

²

combining form

1. indicating earth

   geomorphology

geo–

1. A prefix that means “earth,” as in geochemistry, the study of the Earth's chemistry.

Word History and Origins

Origin of geo¹

< Greek geō-, combining form of gê the earth

Word History and Origins

Origin of geo¹

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

Origin of geo²

from Greek, from gē earth

Example Sentences

The Desert View Annex, an adjacent facility also operated by the GEO Group, held 451.

From Los Angeles Times

The facility is overseen by Immigration Customs and Enforcement and GEO Group, a Florida-based private prison corporation.

From Los Angeles Times

Most immigrant detainees are held in facilities that are run by private prison companies, including the Florida-based GEO Group and Tennessee-based CoreCivic.

From Los Angeles Times

Before becoming attorney general, Pam Bondi lobbied extensively for GEO Group, a major private prison company—the latest glaring example in a long-standing revolving door between the industry and the BOP.

From Slate

Private prison operators like GEO Group, which manages Immigration and Customs Enforcement detention centers, increased their lobbying activity in 2024 and early 2025.

From Slate

When To Use

What does geo- mean?

Geo- is a combining form used like a prefix meaning “earth.” It is often used in scientific terms in a variety of fields. In some rare instances, such as the term geocode, geo- is used as an abbreviation of geographical.Geo- comes from Greek gê, meaning “earth.” A synonym of gê is khthṓn, which is the source of several words related to the underworld, such as chthonic.What are variants of geo-?When combined with words or word elements that begin with a vowel, geo- becomes ge-, as in geanticline. Want to know more? Read our Words That Use article for ge-.