Thermal

a.	1.	Of or pertaining to heat; warm; hot; as, the thermal unit; thermal waters. The thermal condition of the earth. - J. D. Forbes.
	2.	caused by or affected by heat; as, thermal springs.
	3.	designed to retain heat; as, thermal underwear. Thermal conductivity See under Conductivity, and Spectrum. Thermal unit (Physics) a unit chosen for the comparison or calculation of quantities of heat. The unit most commonly employed is the amount of heat necessary to raise the temperature of one gram or one pound of water from zero to one degree Centigrade. See Calorie, and under Unit.

Noun	1.	thermal - rising current of warm air
Adj.	1.	thermal - relating to or associated with heat; "thermal movements of molecules"; "thermal capacity"; "thermic energy"; "the caloric effect of sunlight" Synonyms: caloric, thermic Antonyms: nonthermal - not involving heat; "nonthermal luminescence"
	2.	thermal - of or relating to hot a hot spring; "thermal water"
	3.	thermal - caused by or designed to retain heat; "a thermal burn"; "thermal underwear"

aestival, blood-hot, blood-warm, calid, equatorial, fire storm, genial, hot air, luke, lukewarm, mild, room-temperature, subtropical, summery, sunny, sunshiny, superheated air, temperate, tepid, thermic, toasty, tropical, unfrozen, warm, warm as toast, warmish