thermal

adjective
ther·​mal | \ˈthər-məl \

Definition of thermal 

(Entry 1 of 2)

1a : of, relating to, or caused by heat thermal stress thermal insulation

b : being or involving a state of matter dependent upon temperature thermal conductivity thermal agitation of molecular structure

c : having low energies of the order of those due to thermal agitation thermal neutrons

2 : designed (as with insulating air spaces) to prevent the dissipation of body heat thermal underwear

3 [ Latin thermae public baths, from Greek thermai, plural of thermē ] : of, relating to, or marked by the presence of hot springs thermal waters

thermal

noun

Definition of thermal (Entry 2 of 2)

: a rising body of warm air

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Other Words from thermal

Adjective

thermally \ ˈthər-​mə-​lē \ adverb

Did You Know?

In days gone by, much of the male population of the northern states in the cold months would wear a garment of thermal underwear covering the entire body, called a union suit. Union suits kept sodbusters, cowboys, and townsfolk alike not only warm but also itchy and a little on the smelly side (back when bathing once a week was considered the height of cleanliness). Thermal imaging is photography that captures "heat pictures"--rather than ordinary light pictures--of objects. And thermal pollution occurs when industrial water use ends up warming a river in a damaging way. Small-plane pilots use thermal as a noun for a warm updraft, often over a plowed field or desert, that lifts their wings, just as it enables hawks to soar upward without moving their wings.

Examples of thermal in a Sentence

Recent Examples on the Web: Adjective

One of the crown jewels of the modernization efforts are the new goggles that use thermal technology to see through smoke and darkness. Jim Michaels, USA TODAY, "Army's new weapon: 'Enemy can’t see we’re targeting him until we pull the trigger'," 9 May 2018 On Friday, the Medical Examiner’s Office said Carole Paladino died of multiple blunt trauma and John Paladino succumbed to thermal injuries. Max Cohen, Philly.com, "House explosion that killed Gloucester County couple was accidental, fire marshal rules," 13 July 2018 Families and children rested under shiny thermal blankets in cells of chain-link fences adorned with high-hanging televisions. Washington Post, "A day with Border Patrol: imperiled infant, distraught dad," 26 June 2018 Families and children rested under shiny thermal blankets in cells of chain-link fences adorned with high-hanging televisions. Elliot Spagat, The Seattle Times, "A day with Border Patrol: imperiled infant, distraught dad," 25 June 2018 The detention facilities themselves have generated condemnation, showing kids sitting behind cage-like chain link fencing or lying on mattresses with silver thermal blankets. Jen Kirby, Vox, "The 2,300 migrant kids already separated won’t immediately be reunited with parents," 21 June 2018 Videos of children under foil-like thermal blankets in warehouses, separated in basically large chain-link boxes, are tough to watch. Michael Smolens, sandiegouniontribune.com, "Trump creates kids crisis to leverage border wall, immigration limits," 18 June 2018 To avoid this, the instruments—which dot the outside of the back of the craft—are wrapped in thermal blankets and paired with individual, solar-powered heaters. Beth Mole, Ars Technica, "This spacecraft will get closer to the Sun than any before it—without melting," 29 Mar. 2018 Every spring for the past eight years, residents from the neighboring Obergoms area have trekked up the Swiss mountain to wrap thermal blankets around parts of the glacier and the ice grotto carved inside it. Helena Bachmann, USA TODAY, "The Swiss found a way to save this glacier from melting: Wrap it in a giant blanket," 13 Mar. 2018

Recent Examples on the Web: Noun

His daily wardrobe never veers far from a T-shirt over a long-sleeve thermal. Jessica Radloff, Glamour, "The Big Bang Theory," 25 Oct. 2018 Seko said utilities were planning to start up several other thermal and hydroelectric plants to provide at least some power. Fox News, "At least 7 dead, dozens feared buried after quake hits northern Japan," 2 Oct. 2018 The 13-, 15-, and 17-inch Inspiron 7000 two-in-ones now have the new thermal system found in the Inspiron Chromebook, featuring vents behind the hinges. Valentina Palladino, Ars Technica, "Dell tempts Pixelbook lovers with premium $599 Inspiron Chromebook 14," 29 Aug. 2018 To accommodate improved thermals and upgraded processor and graphics options, the new Spectre 15 x360 is about 1.67mm thicker than the previous model, as well as a bit heavier (4.5 pounds instead of 4.4 pounds). Valentina Palladino, Ars Technica, "HP Spectre 15 x360 2018 review: Made better by standard 4K, great battery life," 25 May 2018 To release the atmosphere’s CAPE, thermals near the surface need to be nudged upward in an organized manner. Jeff Halverson, Washington Post, "Severe thunderstorm watch: Storms approaching D.C.’s southern suburbs," 10 May 2018 Core 10 Be Warm Thermal Fitted Run Hoodie: The ultimate lightweight thermal, this hoodie is perfect for all-season running; just pull it on and go. Susan Brickell, Health.com, "Amazon Just Leaked an Early Prime Day Deal—and It’s Perfect for Fitness Junkies," 12 July 2018 All of the cells were outfitted with metal benches and some sleeping mats and disposable aluminum thermal blankets scattered about. Alicia A. Caldwell, WSJ, "Along the Border, Migrant Mothers Turn Themselves In to Immigration Authorities," 26 June 2018 The La Porte plant, of course, is just a demonstration project, but Dimmig said NET Power has essentially built a 300MW plant scaled down to 25MW electric/50MW thermal. Megan Geuss, Ars Technica, "In Texas, a new power plant could redefine carbon capture," 31 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'thermal.' 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 thermal

Adjective

1742, in the meaning defined at sense 3

Noun

1933, in the meaning defined above

History and Etymology for thermal

Adjective

Greek thermē

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Statistics for thermal

Last Updated

29 Oct 2018

Look-up Popularity

Time Traveler for thermal

The first known use of thermal was in 1742

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More Definitions for thermal

thermal

adjective

English Language Learners Definition of thermal

 (Entry 1 of 2)

: of, relating to, or caused by heat

: designed to keep you warm by preventing heat from leaving your body

: having hot water flowing out of the ground

thermal

noun

English Language Learners Definition of thermal (Entry 2 of 2)

: a rising current of warm air that is produced when the sun heats an area of the ground

thermals : thermal clothing or underwear

thermal

adjective
ther·​mal | \ˈthər-məl \

Kids Definition of thermal

: of, relating to, or caused by heat thermal insulation

thermal

adjective
ther·​mal | \ˈthər-məl \

Medical Definition of thermal 

1 : of, relating to, or caused by heat tactile and thermal senses

2 : being or involving a state of matter dependent upon temperature thermal agitation of molecular structure

Other Words from thermal

thermally \ -​mə-​lē \ adverb

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Comments on thermal

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