Dictionary.com
Thesaurus.com

geothermal

American  
[jee-oh-thur-muhl] / ˌdʒi oʊˈθɜr məl /
Or geothermic

adjective

  1. of or relating to the internal heat of the earth.


geothermal British  
/ ˌdʒiːəʊˈθɜːməl /

adjective

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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

geothermal Scientific  
/ jē′ō-thûrməl /
  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.


Etymology

Origin of geothermal

First recorded in 1870–75; geo- + thermal

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.

Keep Reading on Vocabulary.com

Vocabulary lists containing geothermal

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

As a result, hyperscalers are making major commitments to next-generation nuclear, nascent geothermal and natural-gas plants that capture the carbon they produce.

From The Wall Street Journal Sep. 1, 2026

Geothermal company Fervo Energy struck a deal to sell power to Alphabet’s Google from a Utah project that it plans to turn into the world’s largest enhanced geothermal facility.

From The Wall Street Journal Sep. 1, 2026

Jacobson said the state can — and should — shut Diablo Canyon down on time and still meet its climate goals through a combination of wind, geothermal, rooftop solar and imported supplies.

From Los Angeles Times Aug. 16, 2026

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

From Los Angeles Times Aug. 12, 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

Vocabulary.com logo
by dictionary.com

Dictionary.com's Learning Companion

Go beyond just looking up words.
Remember them forever with VocabTrainer.

Start training