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]