bestill (v.)

word-forming element of verbs and nouns from verbs, with a wide range of meaning: "about, around; thoroughly, completely; to make, cause, seem; to provide with; at, on, to, for;" from Old English be- "about, around, on all sides" (the unstressed form of bi "by;" see by (prep.)). The form has remained by- in stressed positions and in some more modern formations (bylaw, bygones, bystander).

The Old English prefix also was used to make transitive verbs and as a privative prefix (as in behead). The sense "on all sides, all about" naturally grew to include intensive uses (as in bespatter "spatter about," therefore "spatter very much," besprinkle, etc.). Be- also can be causative, or have just about any sense required. The prefix was productive 16c.-17c. in forming useful words, many of which have not survived, such as bethwack "to thrash soundly" (1550s) and betongue "to assail in speech, to scold" (1630s).

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.