Of or pertaining to heat; warm; hot; as, the thermal unit; thermal waters.
Webster's Revised Unabridged Dictionary (1913), edited by Noah Porter. About
\ther"mal\ (?), a. [l. thermae hot springs, fr. gr. &?;, pl. of &?; heat, fr. &?; hot, warm, &?; to warm, make hot; perhaps akin to l. formus warm, and e. forceps.] of or pertaining to heat; warm; hot; as, the thermal unit; thermal waters. the thermal condition of the earth. d. forbes.
spectrum. see under conductivity, and spectrum.
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.
1. relating to or associated with heat; "thermal movements of molecules"; "thermal capacity"; "thermic energy"; "the caloric effect of sunlight" [syn: thermic, caloric]
2. caused by or designed to retain heat; "thermal springs"; "a thermal burn"; "thermal underwear" n : rising current of warm air