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

Other Words from thermal Did You Know? More Example Sentences Learn More about thermal

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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

The rifle was paired with a helmet whose eyepiece showed, with night vision and thermal vision, where the rifle was pointed as well as what was directly in front of the soldier. — Sabrina Schnur, BostonGlobe.com, "US Army researchers in Natick display new technology at the State House," 19 June 2019 Other system additions include networked thermal cameras installed along the reserve's perimeter and fiber-optic acoustic sensors. — Sean Gallagher, Ars Technica, "We know you hate the Internet of Things, but it’s saving megafauna from poachers," 6 June 2018 Ray Radakovich, of the Greenfield Police Department, said his agency purchased the thermal-vision drone four months ago. — Elliot Hughes, Milwaukee Journal Sentinel, "Spike strip, K-9, drone used to apprehend fleeing suspect in Greenfield," 12 Apr. 2018 In a press release, Shine says that the Goldilocks Zone may be turtles’ defense against thermal conditions linked with shifting temperatures. — Meilan Solly, Smithsonian, "Turtle Embryos May Be Able to Influence Their Sex by Moving Around Inside the Egg," 2 Aug. 2019 Soot is landing in Greenland because of the wildfires, making the ice sheet darker and and therefore absorbing more thermal energy and melting quicker, says Holthaus. — Jasmine Aguilera, Time, "Siberian Wildfires and Heatwaves in Alaska: How the Arctic Is Nearing a Point of No Return," 2 Aug. 2019 The unidentified active-duty soldier was first detected by thermal imaging equipment moving south near the Imjin River late on Wednesday, and South Korean troops took him into custody just before midnight, the JCS said. — NBC News, "North Korean soldier defects across the DMZ, South Korea says," 1 Aug. 2019 Optional screens and various tints are available to reduce glare and harmful UV rays, and to improve the thermal performance of your existing windows. — Stacy Argo, Houston Chronicle, "GHBA Remodelers Council: Consider adding storm windows to your home," 28 July 2019 Last fall, forestry officials launched a military-style operation, deploying drones, thermal cameras, hundreds of officers and veterinarian sharpshooters mounted on the backs of elephants, to tranquilize the tiger. — New York Times, "Tiger Is Beaten to Death on Video, Outraging India," 26 July 2019

Recent Examples on the Web: Noun

Aviators can't use autopilot in trying conditions that can range from thermals rising out of flaming forests to flying low through mountain ranges. — Meg Jones, Milwaukee Journal Sentinel, "Firefighting planes and their crews spotlighted at EAA AirVenture," 27 July 2019 Buy Now: Tangle Teezer Hairbrush, $7.60 (originally $12) Olaplex Hair Perfector No. 3 Treatment Created by two chemistry PhDs, this reparative hair treatment relinks hair bonds broken by chemical, thermal, and mechanical processes. — Cnt Editors, Condé Nast Traveler, "The Best Amazon Prime Day Beauty Deals for Frequent Travelers," 16 July 2019 After all these years, the world’s very first national park is still one of its most imposing, a blend of land and water, forest and field, wildlife and geo-thermal features that often seem to be living things. — Dan Westergren, National Geographic, "Yellowstone National Park," 12 Apr. 2019 Turkey vultures circled overhead, riding the thermals against a backdrop of bright blue Colorado sky. — Sarah Kuta, The Know, "What are via ferratas and why is Colorado so crazy about them?," 2 July 2019 The parents are showing them how to survive, how to find food, how to navigate thermals. — San Diego Union-Tribune, "Column: Why the Safari Park’s California condor dads are Father’s Day stars," 14 June 2019 That alone is big news, but there are other welcome improvements with this generation, from display and color choices to thermals. — Melissa Riofrio, PCWorld, "Finally! The new Dell XPS 13 puts the camera in the right place," 8 Jan. 2019 Take thermals, columns of rising air that form when the ground below warms through sunlight. — David Grossman, Popular Mechanics, "Vultures Use Social Networks to Share Crucial Flight Information," 8 Nov. 2018 Matek is a new base-layer brand built for the slopes, but its thermals are chic enough to wear on their own with a skirt or jeans. — Anny Choi, Vogue, "5 Cold-Weather Styling Tricks You Can Take to the Office," 19 Jan. 2019

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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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

British : thermal clothing or underwear

See the full definition for thermal in the English Language Learners Dictionary

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

thermal

Definition of thermal

Other Words from thermal

Did You Know?

Examples of thermal in a Sentence

First Known Use of thermal

History and Etymology for thermal

English Language Learners Definition of thermal

Kids Definition of thermal

Medical Definition of thermal

thermal

Definition of thermal

Other Words from thermal

Did You Know?

Examples of thermal in a Sentence

First Known Use of thermal

History and Etymology for thermal

English Language Learners Definition of thermal

Kids Definition of thermal

Medical Definition of thermal

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