c. 1600, of a letter, "not sounded," from Latin quiescentem (nominative quiescens), present participle of quiescere, inchoative verb formed from quies "rest, quiet" (from suffixed form of PIE root *kweie- "to rest, be quiet"). From 1640s as "resting, being in a state of repose." Related: Quiescently.
"rest, repose, quiet, tranquility," 1590s, from French quiétude (c. 1500) or directly from Late Latin quietudo, from Latin quietus "free; calm, resting" (from PIE root *kweie- "to rest, be quiet"). In the same sense quietness is attested from mid-15c.
Old English stillan "to be still, have rest; to quiet, calm, appease; to stop, restrain," from stille "at rest" (see still (adj.)). Cognate with Old Saxon stillian, Old Norse stilla, Dutch, Old High German, German stillen. Related: Stilled; stilling.
"to rest or place on or as on a pillow," 1620s, from pillow (n.). Related: Pillowed; pillowing.