What does the prefix geo- mean?
Geo- comes from the Greek ge, which means "Earth". It shows a relation to the planet, the ground or territory. Even the word geometry started here: it originally meant "measuring the land".
ESEN
Prefix · earth / land
geo-
Signals relation to the Earth or geography: geography, geology, geometry, geothermal.
Scientific
Written by Bryan López, English teacher · Updated
Geo- today also talks about location
Geo- left the Earth sciences and reached technology: now it also talks about locations, coordinates and maps on phones and apps. Every time something is related to "where you are" in the physical world, it likely carries geo-. It is a prefix you will see a lot when using apps.
How it is used
Attaches to nouns and adjectives:
- geo- + field of studygraphy → geographylogy → geologyphysics → geophysicschemistry → geochemistry
- geo- + technical/political termpolitics → geopoliticsthermal → geothermallocation → geolocationmetry → geometry
How it is pronounced
geo-/dʒiːəʊ/
Tap the button to hear how the prefix sounds. Each word in the table has its own audio.
Examples
Root word
With geo-
In a phrase
- graphygeographyHer geography teacher inspired her to travel to every continent.
- logygeologyGeology revealed the rock layers exposed during the tunnel construction.
- metrygeometryArchitects use geometry to calculate angles and structural dimensions.
- thermalgeothermalIceland generates most of its electricity from geothermal energy.
- politicsgeopoliticsThe conflict was driven by geopolitics and competition over resources.
- locationgeolocationThe app uses geolocation to find coffee shops near you.
- physicsgeophysicsGeophysics uses seismic data to map the Earth's interior.
Common mistakes
geometry = measuring the Earth (only about geography)
geometry = a branch of mathematics about shapes and space, originating in land measurement
"Geometry" comes from geo- (Earth) + metry (measurement) because it began as practical land measurement in ancient Egypt and Greece. Today it is an abstract mathematical field that goes far beyond measuring land.
geolocation = a map
geolocation = the technology that determines the geographic position of a device
"Geolocation" is the process of identifying where a device is using GPS, IP address, or network signals. A map is a visual representation; geolocation is the technological process of determining coordinates.
A trick to remember it
Think of geography, mapping the Earth: geo- = earth. geography, geology.
Practise what you learned
Exercise 1 · Form the word
Exercise 2 · Pick the right one
"She used the app's ___ feature to find all coffee shops within five kilometres of her position."
Exercise 3 · Pick the right one
Why does "geometry" start with "geo-" if it is a branch of mathematics, not geography?
Frequently asked questions
What does the prefix geo- mean in English?
The prefix geo- signals relation to the Earth or geography: geography, geology, geometry, geothermal.
How do you pronounce geo-?
The prefix geo- is pronounced /dʒiːəʊ/. For example, "geography".
Can you give an example of a word with geo-?
"graphy" becomes "geography". It is a typical example of the geo- prefix.
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