The Collaborative International Dictionary of English v.0.48:

Before \Be*fore"\, prep. [OE. beforen, biforen, before, AS.
   beforan; pref. be- + foran, fore, before. See Be-, and
   Fore.]
   1. In front of; preceding in space; ahead of; as, to stand
      before the fire; before the house.
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            His angel, who shall go
            Before them in a cloud and pillar of fire. --Milton.
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   2. Preceding in time; earlier than; previously to; anterior
      to the time when; -- sometimes with the additional idea of
      purpose; in order that.
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            Before Abraham was, I am.             --John viii.
                                                  58.
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            Before this treatise can become of use, two points
            are necessary.                        --Swift.
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   Note: Formerly before, in this sense, was followed by that.
         "Before that Philip called thee . . . I saw thee."
         --John i. 48.
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   3. An advance of; farther onward, in place or time.
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            The golden age . . . is before us.    --Carlyle.
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   4. Prior or preceding in dignity, order, rank, right, or
      worth; rather than.
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            He that cometh after me is preferred before me.
                                                  --John i. 15.
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            The eldest son is before the younger in succession.
                                                  --Johnson.
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   5. In presence or sight of; face to face with; facing.
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            Abraham bowed down himself before the people. --Gen.
                                                  xxiii. 12.
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            Wherewith shall I come before the Lord? --Micah vi.
                                                  6.
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   6. Under the cognizance or jurisdiction of.
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            If a suit be begun before an archdeacon. --Ayliffe.
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   7. Open for; free of access to; in the power of.
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            The world was all before them where to choose.
                                                  --Milton.
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   Before the mast (Naut.), as a common sailor, -- because the
      sailors live in the forecastle, forward of the foremast.


   Before the wind (Naut.), in the direction of the wind and
      by its impulse; having the wind aft.
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The Collaborative International Dictionary of English v.0.48:

Before \Be*fore"\, adv.
   1. On the fore part; in front, or in the direction of the
      front; -- opposed to in the rear.
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            The battle was before and behind.     --2 Chron.
                                                  xiii. 14.
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   2. In advance. "I come before to tell you." --Shak.
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   3. In time past; previously; already.
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            You tell me, mother, what I knew before. --Dryden.
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   4. Earlier; sooner than; until then.
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            When the butt is out, we will drink water; not a
            drop before.                          --Shak.
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   Note: Before is often used in self-explaining compounds; as,
         before-cited, before-mentioned; beforesaid.
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WordNet (r) 3.0 (2006):

before
    adv 1: earlier in time; previously; "I had known her before";
           "as I said before"; "he called me the day before but your
           call had come even earlier"; "her parents had died four
           years earlier"; "I mentioned that problem earlier" [syn:
           earlier, before]
    2: at or in the front; "I see the lights of a town ahead"; "the
       road ahead is foggy"; "staring straight ahead"; "we couldn't
       see over the heads of the people in front"; "with the cross
       of Jesus marching on before" [syn: ahead, in front,
       before]

Moby Thesaurus II by Grady Ward, 1.0:

83 Moby Thesaurus words for "before":
   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