geo·​ther·​mal | \ ˌjē-ō-ˈthər-məl How to pronounce geothermal (audio) \

Definition of geothermal

: of, relating to, or utilizing the heat of the earth's interior also : produced or permeated by such heat geothermal steam geothermal regions

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Other Words from geothermal

geothermally \ ˌjē-​ō-​ˈthər-​mə-​lē How to pronounce geothermally (audio) \ adverb

Did You Know?

Geothermal comes partly from the Greek thermos, "hot". Most geothermal electricity is provided by power plants situated in areas where there is significant activity of the Earth's great tectonic plates—often the same areas where volcanoes are found. But hot water from deep underground may be used by cities far from volcanoes to heat buildings or sidewalks. And a newer source of geothermal energy relies on a less dramatic kind of heat: Individual homeowners can now install heat pumps that take advantage of the 50°-60° temperature of the soil near the surface to provide heating in cold weather (and air-conditioning in the warm months). These very small-scale geothermal systems may eventually supply more useful energy than the large power plants.

Examples of geothermal in a Sentence

Recent Examples on the Web Relax in a pool bubbling with geothermal energy, but play it safe by staying hydrated, cooling down and avoiding alcohol and drugs. oregonlive, "Getaways with a wedding theme: Say ‘I do’ or honeymoon here," 3 July 2020 Other assets of the house include energy-saving systems like geothermal heating with propane backup. Judy Rose, Detroit Free Press, "Mix of woods and glass give inhabitants of $3.45M log home soaring views of nature," 27 June 2020 Relax in a pool bubbling with geothermal energy, but play it safe by staying hydrated, cooling down and avoiding alcohol and drugs. oregonlive, "Get away to an Oregon vacation home with a dock: Make a splash with the whole family," 19 June 2020 One of the best things to do in Iceland is to visit its beautiful and relaxing geothermal lagoons. Andrea Romano, Travel + Leisure, "Iceland’s Newest Geothermal Lagoon Will Have Sweeping Ocean Views and Swim-up Bar (Video)," 15 June 2020 Relax in a pool bubbling with geothermal energy, but play it safe by staying hydrated, cooling down and avoiding alcohol and drugs. oregonlive, "Oregon getaways for the whole family: Are you ready to plan for fun on the water?," 12 June 2020 Pagosa Springs is home to the world’s deepest geothermal hot spring and is a popular spa destination. Matt Wyatt,, "Pagosa Springs: Gateway to San Juan Mountains and base camp for anglers," 6 June 2020 The Svartsengi power station sits on the banks of the Blue Lagoon, an artificial geothermal spring and one of Iceland’s most popular tourist attractions. Daniel Oberhaus, Wired, "Cheap Nanoparticles Pave the Way for Carbon-Neutral Fuel," 19 Feb. 2020 Shade and Tobin also identified heat-loving bacteria (thermophiles) that resembled microbes living near geothermal hot springs in Iceland, though their data wasn’t detailed enough to say just how closely the organisms were related. Carrie Arnold, WIRED, "A Blazing Hot Coal Seam Shows How Microbes Can Spring to Life," 21 Apr. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'geothermal.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of geothermal

1875, in the meaning defined above

History and Etymology for geothermal

geo- + thermal entry 1

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Time Traveler for geothermal

Time Traveler

The first known use of geothermal was in 1875

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Statistics for geothermal

Last Updated

10 Jul 2020

Cite this Entry

“Geothermal.” Dictionary, Merriam-Webster, Accessed 15 Jul. 2020.

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More Definitions for geothermal


How to pronounce geothermal (audio)

English Language Learners Definition of geothermal

: of, relating to, or using the natural heat produced inside the Earth also : produced by such heat

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