thermal

adjective
ther·​mal | \ ˈthər-məl How to pronounce thermal (audio) \

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

Keep scrolling for more

Other Words from thermal

Adjective

thermally \ ˈthər-​mə-​lē How to pronounce thermal (audio) \ 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 Workers use handheld thermal cameras to inspect equipment during periodic inspections. Robert Kester, Forbes, 14 Oct. 2021 Law enforcement is flying overnight, using thermal imaging in hopes of finding the 23-year-old who is a person of interest in the case of Petito, CBS affiliate WTSP reported, citing law enforcement sources. Sarah Lynch Baldwin, CBS News, 23 Sep. 2021 On top of the vibrant blue hue that forms the base of the set are colorful mismatched blobs that resemble thermal heat imaging. Gabi Thorne, Allure, 21 Sep. 2021 Most are using their [primary] weapons with [optical] weapons sights and thermal imaging. Eric Tegler, Forbes, 17 Sep. 2021 First responders were using thermal imaging from drones to search the building, according to officials. Ivan Pereira, ABC News, 12 Sep. 2021 But of course: Collins' face turns into a colorful blob rendered by thermal imaging. Billboard, 29 July 2021 An airplane equipped with highly sensitive thermal-imaging technology scanned the ridge line for human body heat on four consecutive nights. Nora Mishanec, San Francisco Chronicle, 22 July 2021 Combining all three and potentially others like near infrared or thermal imaging cameras can provide even more roboust and reliable sensing in all weather and lighting conditions. Sam Abuelsamid, Forbes, 2 Sep. 2021 Recent Examples on the Web: Noun With lockdowns lifting, many employers plan to use systems, including fever-detecting thermal cameras, mask-checking systems and corporate contact-tracing devices, to help prevent new Covid-19 outbreaks. Stephanie Bodoni, Bloomberg.com, 1 June 2020 Fever-checking thermal cameras are also starting to become ubiquitous. Helene Fouquet, Fortune, 23 May 2020 Fever-checking thermal cameras are also starting to become ubiquitous. Helene Fouquet, Fortune, 23 May 2020 Fever-checking thermal cameras are also starting to become ubiquitous. Helene Fouquet, Bloomberg.com, 20 May 2020 Some airports, such as London Heathrow, Puerto Rico's San Juan airport, and Paine Field—a secondary airport in Seattle—are using thermal cameras to scan crowds for feverish temperatures. Jessica Puckett, Condé Nast Traveler, 12 May 2020 In Florida's Palm Beach County, Dahua thermal cameras sold by RedSpeed and installed last month scan everyone who enters the county jail and courthouse, while a deputy with a laptop reviews people's temperatures from nearby. Drew Harwell, Anchorage Daily News, 11 May 2020 In Midtown Manhattan, thermal cameras will measure body temperatures as employees file into a 32-story office tower at Rockefeller Center. Konrad Putzier And Chip Cutter, WSJ, 5 May 2020 More than 1,500 thermal cameras were shipped to Amazon warehouses by China’s Zhejiang Dahua Technology, and at least 500 of the cameras are being sold within the U.S., Reuters reported Wednesday citing three sources. Spencer Neale, Washington Examiner, 29 Apr. 2020

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.

See More

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

Keep scrolling for more

Learn More About thermal

Time Traveler for thermal

Time Traveler

The first known use of thermal was in 1742

See more words from the same year

Dictionary Entries Near thermal

Thermaïkós Kólpos

thermal

thermal agitation

See More Nearby Entries 

Statistics for thermal

Last Updated

17 Oct 2021

Cite this Entry

“Thermal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/thermal. Accessed 20 Oct. 2021.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon
Seen & Heard
People are talking about

Keep scrolling for more

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
: thermal clothing or underwear

thermal

adjective
ther·​mal | \ ˈthər-məl How to pronounce thermal (audio) \

Kids Definition of thermal

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

thermal

adjective
ther·​mal | \ ˈthər-məl How to pronounce thermal (audio) \

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 How to pronounce thermal (audio) \ adverb

More from Merriam-Webster on thermal

Nglish: Translation of thermal for Spanish Speakers

Britannica English: Translation of thermal for Arabic Speakers

WORD OF THE DAY

Test Your Vocabulary

Difficult Spelling Words Quiz

  • alphabet pasta spelling help
  • Which is the correct spelling?
True or False

Test your knowledge - and maybe learn something along the way.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!