- chill (n.)
- Old English ciele, cele "cold, coolness, chill, frost," from Proto-Germanic *kal- "to be cold," from PIE root *gel- "cold" (see cold). According to OED, the word seems to have been obsolete after c.1400 (displaced by cold) and the modern use is a back-formation since c.1600 from the verb.
- chill (v.)
- late 14c., intransitive, "to feel cold, grow cold;" c.1400, transitive, "to make cold," from chill (n.). Related: Chilled; chilling; chillingly. Figurative use from late 14c. Meaning "hang out" first recorded 1985; from earlier (1979) sense of chill out "relax."