Prefix · earth / land
Signals relation to the Earth or geography: geography, geology, geometry, geothermal.
Written by Bryan López, English teacher · Updated
Geo- comes from Greek "ge" or "gaia" (Earth) and signals a relation to the planet Earth or to the ground: geography = description of the Earth; geology = the study of rocks and Earth's composition; geometry = measurement of the Earth (mathematics rooted in spatial measure); geothermal = energy from the Earth's internal heat; geopolitics = politics related to territory.
In modern use, geo- has extended beyond the geosciences: geolocation = location based on Earth coordinates; geotagging = adding location data to images or digital posts; geofencing = a virtual boundary defined by GPS coordinates. In technology, geo- signals a relationship to physical location in terrestrial space.
Attaches to nouns and adjectives. Identical in Spanish and English:
Pronunciation: /dʒiːəʊ/, with a soft "g" as in "gene." Identical in Spanish and English.
geo-/dʒiːəʊ/
Tap the button to hear how the prefix sounds. Each word in the table has its own audio.
"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" 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
Geo- = "Earth" or "land": geography = description of the Earth, geology = the science of rocks, geometry = measurement of space (originally of land plots), geothermal = heat from inside the Earth. Identical in Spanish and English in almost every word.
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?
The prefix geo- signals relation to the Earth or geography: geography, geology, geometry, geothermal. In Spanish it usually maps to geo-.
The prefix geo- is pronounced /dʒiːəʊ/. For example, "geography".
"graphy" becomes "geography". It is a typical example of the geo- prefix.
un-, re-, pre-, dis-, over-, in-... every beginning you need to unlock thousands of English words at once.