Definition of thermal in English:

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Pronunciation: /ˈTHərməl/


1Relating to heat.
Example sentences
  • In other words, water vapor has a low heat capacity and poor thermal conduction.
  • Approximately 35% of the energy from a nuclear explosion is an intense burst of thermal radiation, ie heat.
  • Basic research into the electrical and thermal properties of metallic, magnetic and organic materials is leading to the discovery of novel superconductors.
1.1 another term for geothermal.
Example sentences
  • She is the daughter of Aramkumar, an engineer at the thermal power station in Tuticorin, and Annam, who is an engineer at the Tamil Nadu Water and Drainage Board.
  • Work is also continuing on the refurbishment of two units at a large thermal power station in south Baghdad.
  • Leaving his job as a designer of thermal power stations, he took a plunge into politics.
1.2(Of a garment) made of a fabric that provides exceptional insulation to keep the body warm: thermal underwear
More example sentences
  • A former Miss UK who traded her swimsuit for thermal underwear and fleecy jackets to compete in the world's toughest endurance challenge is keeping pace with the leaders after a slow start.
  • Cold weather gloves, jackets and insulated flying boots combined with thermal underwear will keep you warm during a flight and can save your life in an emergency.
  • It has not been much warmer in France than it was in Belgium and we started the first stage in leg warmers, thermal vests, gloves and hats.


1An upward current of warm air, used by gliders, balloons, and birds to gain height.
Example sentences
  • By using thermals, gliders can stay aloft for hours without using power.
  • Before too much height is lost, the pilot will seek another thermal, gain height in it, and then set off on course yet again.
  • It indicates what rate of climb you seem to be expecting in the next thermal based on your current air speed.
2 (usually thermals) A thermal garment, especially underwear.
Example sentences
  • For sailing I would advise packing at least the same amount of clothes, thermals, jerseys and long johns again.
  • It works for pottering around in barefoot at home or layered up with thermals, tights and a cardie for winter workdays.
  • I was bundled up in only one coat and a long-sleeved tee shirt, with some thermals and pants over them, along with hiking boots.



Pronunciation: /ˈTHərməlē/
Example sentences
  • An earlier order bans the import of live birds, eggs and thermally unprocessed bird products from 17 countries and regions in East and South Asia.
  • A lone, single bomb, thermally guided, had hit the electric substation outside the perimeter of the complex, causing little damage.
  • The complex will be built with thermally efficient non-toxic timber panels, which should mean residents have a pleasant surprise when the energy bill arrives.


Mid 18th century (in the sense 'relating to hot springs'): from French, from Greek thermē 'heat'.

Words that rhyme with thermal

epidermal, geothermal, isothermal, pachydermal, taxidermal

For editors and proofreaders

Syllabification: ther·mal

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