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.

The Imperial Valley is a key interconnection point for regional solar, geothermal and battery storage projects.

From Los Angeles Times • May 17, 2026

Wart van Zonneveld proudly showed me their geothermal well, which pumps water up from 3km below the surface, at a temperature of 102C.

From BBC • May 14, 2026

Historically, companies have only been able to operate geothermal plants in a few locations that have the right mix of water and heat underground.

From Barron's • May 13, 2026

It has quickly emerged as a champion of so-called enhanced geothermal.

From The Wall Street Journal • May 13, 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

Look it up. Learn it forever.

Remember "geothermal" for good with VocabTrainer. Expand your vocabulary effortlessly with personalized learning tools that adapt to your goals.

Take me to Vocabulary.com