- heat
- O.E. hætu, hæto, from P.Gmc. *khaitin- "heat," from *khaitaz "hot" (cf. O.S. hittia, O.N. hiti, O.Fris. hete, Ger. hitze "heat," Goth. heito "fever"). The same root is the source of O.E. hat "hot" and hæða "hot weather." The verb is from O.E. hætan, from P.Gmc. *khaitijanam. Meaning "a single course in a race" is from 1663, perhaps from earlier fig. sense of "a single intense effort" (c.1380), or meaning "run given to a horse to prepare for a race" (1577). Meaning "sexual excitement in animals" is from 1768. Meaning "trouble with the police" attested by 1920. Heat wave "period of excessive hot weather" first attested 1893.