geothermal

American  

[jee-oh-thur-muhl] / ˌdʒi oʊˈθɜr məl /

Or geothermic

adjective

1. 

   of or relating to the internal heat of the earth.

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geothermal British  

/ ˌdʒiːəʊˈθɜːməl /

adjective

1. of or relating to the heat in the interior of the earth

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geothermal Scientific  

/ jē′ō-thûr′məl /

1. Relating to the internal heat of the Earth. The water of hot springs and geysers is heated by geothermal sources.

2. ◆ Geothermal energy is power generated from natural steam, hot water, hot rocks, or lava in the Earth's crust. In general, geothermal power is produced by pumping water into cracks in the Earth's crust and then conveying the heated water or steam back to the surface so that its heat can be extracted through a heat exchanger, or its pressure can be used to drive turbines.

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Etymology

Origin of geothermal

First recorded in 1870–75; geo- + thermal

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Explanation

Heat that rises from the center of the earth is geothermal. If you ever have the chance to dip your toes in a natural hot spring, you can feel that geothermal warmth for yourself! Anything that's thermal has to do with heat, from the Greek therme. The prefix geo-, or "earth," makes it clear that this type of heat rises from the planet itself. Hot springs are warmed by geothermal energy. Geothermal energy is also a renewable source of heat and power. Many buildings use geothermal heating and it's also a good way to generate electricity.

Example Sentences

See Examples For:

geothermal

Opened in 2025, the all-electric building, which contains a 200-seat lecture hall, is powered by a geothermal facility that provides heating and cooling.

From MarketWatch ● Oct. 19, 2026

“Oak Street’s” retro-Spielbergian setting is faithful to a geothermal fault.

From Los Angeles Times ● Aug. 12, 2026

Because ambient noise tomography can survey large underground regions relatively quickly and inexpensively, it may provide a useful way to search for geothermal energy and mineral resources.

From Science Daily ● Aug. 5, 2026

Another newcomer that has lost its shine with investors is Fervo Energy, which is adapting fracking techniques to provide geothermal energy.

From The Wall Street Journal ● Jul. 23, 2026

At the center of the camp, water from a geothermal well had been piped into a pair of shallow, steaming pools lined with rocks and shaded by palm trees: Oh-My-God Hot Springs.

From "Into the Wild" by Jon Krakauer

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