thermal

1 of 2

adjective

ther·​mal ˈthər-məl How to pronounce thermal (audio)
1
a
: 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
thermally adverb

thermal

2 of 2

noun

: a rising body of warm air

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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Adjective
Traps were set up in the area as police used thermal technology in an attempt to track and recapture the monkeys, police said earlier this week. Rebecca Cohen, NBC News, 9 Nov. 2024 The increase is attributed to higher seaborne thermal coal pricing. Quartz Bot, Quartz, 8 Nov. 2024
Noun
Because morning thermals rise, this is a common area to catch bucks cruising the first few hours of the day. Josh Honeycutt, Outdoor Life, 14 Nov. 2024 The larger and more spread out V-Cache die that's still 64MB in capacity also likely helps with thermals as the heat production extends over a larger area. PCMAG, 6 Nov. 2024 See all Example Sentences for thermal 

Word History

Etymology

Adjective

Greek thermē

First Known Use

Adjective

1742, in the meaning defined at sense 3

Noun

1933, in the meaning defined above

Time Traveler
The first known use of thermal was in 1742

Dictionary Entries Near thermal

Cite this Entry

“Thermal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/thermal. Accessed 24 Nov. 2024.

Kids Definition

thermal

1 of 2 adjective
ther·​mal ˈthər-məl How to pronounce thermal (audio)
1
: of or relating to a hot spring
thermal springs
2
: of, relating to, caused by, or saving heat
thermal energy
thermal underwear
thermally adverb

thermal

2 of 2 noun
: a rising body of warm air

Medical Definition

thermal

adjective
ther·​mal ˈthər-məl How to pronounce thermal (audio)
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
thermally adverb

More from Merriam-Webster on thermal

Last Updated: - Updated example sentences
Love words? Need even more definitions?

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