Before

Preposition

 * 1) Earlier than (in time).
 * 2) In front of in space.
 * He stood before me.
 * 1) Under consideration, judgment, authority of (someone).
 * ''The case laid before the panel aroused nothing but ridicule.
 * 1) In store for, in the future of (someone).
 * The period before us looks grim because of the economical crisis.
 * 1) In front of, according to a formal system of ordering items.
 * In alphabetical order, "cat" comes before "dog", "canine" before feline".
 * 1) At a higher or greater position in a subjective ranking.
 * ''An entrepreneur puts market share and profit before quality, an amateur intrinsic qualities before economical considerations.

Conjunction

 * 1) in advance of the time when
 * 2)  rather or sooner than

Adverb

 * 1) at an earlier time
 * I've never done this before.
 * 1) in advance

Synonyms

 * (earlier than in time): by, no later than
 * (in front of in space): ahead of, in front of
 * (in front of according to an ordering system): ahead of
 * (at an earlier time): previously
 * (in advance): ahead
 * lest
 * forward, ahead, sooner, prior, earlier.

Antonyms

 * (earlier than in time): after, later than, afterward.
 * (in front of in space): behind
 * (in front of according to an ordering system): after

Derived terms

 * beforehand
 * beforetime

Thesaurus
above, aforetime, ahead, ahead of time, already, ante, before all, before now, beforehand, beforetime, betimes, by choice, by election, by vote, confronting, earlier, early, ere, ere then, erenow, erewhile, erst, erstwhile, facing, first, fore, foremost, foresightedly, formerly, forward, headmost, hereinabove, hereinbefore, heretofore, historically, hitherto, in advance, in advance of, in anticipation, in anticipation of, in front, in front of, in preference, in preference to, in preparation for, in the forefront, in the foreground, in the front, in the future, in the lead, in the past, in times past, once, only yesterday, or ever, preceding, precociously, preferably, prehistorically, previous, previous to, previously, prior to, priorly, rather, rather than, recently, sooner, sooner than, supra, then, theretofore, till, to, to come, to the fore, to the front, until, up ahead, up to, whilom, yesterday, yet