Old English stille "motionless, stable, fixed, stationary," from Proto-Germanic *stilli- (source also of Old Frisian, Middle Low German, Middle Dutch stille, Dutch stil, Old High German stilli, German still), from PIE *stel-ni-, suffixed form of root *stel- "to put, stand, put in order," with derivatives referring to a standing object or place. Meaning "quiet, calm, gentle, silent" emerged in later Old English. Euphemistic for "dead" in stillborn, etc. Still small voice is from KJV:
And he said, Go forth, and stand upon the mount before the LORD. And, behold, the LORD passed by, and a great and strong wind rent the mountains, and brake in pieces the rocks before the LORD; but the LORD was not in the wind: and after the wind an earthquake; but the LORD was not in the earthquake: and after the earthquake a fire; but the LORD was not in the fire: and after the fire a still small voice. [I Kings xix.11-13]
Used as a conjunction from 1722.
"distilling apparatus," 1530s, from Middle English stillen "to distill" (c. 1300), a variant of distillen (see distill).
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.
c. 1200, "a calm," from still (adj.). Sense of "quietness, the silent part" is from c. 1600 (in still of the night). Meaning "a photograph" (as distinguished from a motion picture) is attested from 1916.
"even now, even then, yet" (as in still standing there), 1530s, from still (adj.) in the sense "without change or cessation, continual" (c. 1300); the sense of "even, yet" (as in still more) is from 1730.