Meaning & use
geo
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Meanings
prefixtechnical
Earth; used at the beginning of words about the earth, its surface, or where things are.
Grammar: A combining form, not a separate word; it is joined to a root, as in geology or geography.
Patterns
- geo- + noun
- geo- + -logy
- geo- + -graphy
Geology is the study of rocks and the earth's structure.
The geography of the region makes farming difficult.
Geothermal energy uses heat from inside the earth.
noununcountableinformal
In informal use, geography as a school subject or a person's location in a game or app.
Grammar: Informal and often written without a hyphen; not standard in formal writing.
Patterns
- the geo
- share your geo
I have a geo test tomorrow, so I'm reviewing maps tonight.
The app asks for your geo so it can show nearby restaurants.
Common combinations
- geopolitics
- Geopolitics is the study of how geography affects politics and international relations.
- geocentric
- An old geocentric model placed the earth at the center of the universe.
- geolocation
- The app uses geolocation to find your position on the map.
- geothermal
- Iceland uses geothermal heat to warm many homes.
Synonyms and how they differ
- earth-
- Earth- is a native English combining form meaning the same, as in earth science; geo- is more common in technical terms.
Word family
Commonly confused: geo or gee?
geo vs gee
Gee is an interjection or slang for a thousand dollars; geo- is a prefix meaning earth.
Practice
Which word uses geo- to mean 'earth'?
Choose one answer.
Geology combines geo- 'earth' with -logy 'study', so it means the study of the earth. Geometry uses geo- but refers to measuring the earth in a mathematical sense; geography also uses geo- but is about places, not rocks. Geode is a rock cavity and does not use geo- as a prefix.
Make it your own
Write a sentence using “geo”, then check it and compare it with the examples above.