stillborn (adj.)

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.

Old English boren, alternative past participle of beran (see bear (v.)). The -en of the Middle English past participles tended to drop the -e- in some verbs, especially after vowels, -r-, and -l- , hence also slain, etc., Middle English stoln. "In modern use the connexion with bear is no longer felt; the phrase to be born has become virtually an intr. verb" [OED].

It is attested from early 14c. as "possessing from birth the character or quality described" (born poet, born loser, etc.). It is from 1710 as "innate, inherited;" the colloquial expression in (one's) born days "in (one's) lifetime" is by 1742.  The distinction of born from borne (q.v.) is 17c.