quiet (n.)

c. 1300, "freedom from disturbance or conflict; calm, stillness," from Old French quiete "rest, repose, tranquility" and directly from Latin quies (genitive quietis) "a lying still, rest, repose, peace," from PIE root *kweie- "to rest, be quiet." Late 14c. as "inactivity, rest, repose."

late 14c., "peaceable, at rest, restful, tranquil," from Old French quiet and directly from Latin quietus "calm, at rest, free from exertion," from quies (genitive quietis) "rest," from PIE root *kweie- "to rest, be quiet." As an adverb from 1570s. Related: Quietly; quietness.

late 14c., "subdue, lessen," from quiet (adj.) and in part from Latin quietare. From mid-15c. as "to make silent, cause to be quiet;" intransitive sense of "become quiet, be silent" is from 1791. Related: Quieted; quieting.