thermal


thermal
thermal (adj.) 1756, "having to do with hot springs," from Fr. thermal (Buffon), from Gk. therme "heat," from PIE *ghwerm-/*ghworm- "warm" (Cf. L. fornax "an oven, kiln," formus "warm," O.E. wearm; see WARM (Cf. warm)). Sense of "having to do with heat" is first recorded 1837. The noun meaning "rising current of relatively warm air" is recorded from 1933.

Etymology dictionary. 2014.

Synonyms: