Merriam-Webster Online Dictionary
soon (adverb)1.
a) obsolete at once - immediately
b) without undue time lapse - before long soon after sunrise
2.
in a prompt manner - speedily as soon as possible the sooner the better no sooner said than done
3.
archaic before the usual time
4.
in agreement with one's choice or preference - willingly I'd just as soon walk as drive
Merriam-Webster Online Thesaurus
soon (adverb)1.
at or within a short time
SYNONIMS:
anon, before long, by and by, directly, momentarily, presently, soonRELATED WORDS:
forthwith, immediately, incontinently, instantaneously, instantly, now, promptly, pronto, right away, right now, right off, straightaway, straightway2.
by choice or preference
SYNONIMS:
fain, first, preferably, readily, soon, willinglyRELATED WORDS:
alternately, alternatively, either, instead; electively, optionally; desirably, gladly, wishfully; obligingly, voluntarilyNEAR ANTONYMS:
reluctantly; forcibly, willy-nilly3.
with great speed
SYNONIMS:
apace, briskly, chop-chop, double-quick, fleetly, full tilt, hastily, hell-for-leather, hot, lickety-split, posthaste, presto, pronto, quick, quickly, rapidly, snappily, soon, speedily, swift, swiftlyRELATED WORDS:
immediately, promptly, readily; impetuously, impulsively, rashly, recklessly; abruptly, suddenly; energetically, vigorouslyNEAR ANTONYMS:
laggardly, lingeringly, ploddingly, sluggishly; deliberately, leisurely; belatedly, delinquently, tardily