The Collaborative International Dictionary of English v.0.48:

Vantage \Van"tage\, v. t.
   To profit; to aid. [Obs.] --Spenser.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Vantage \Van"tage\ (v[.a]n"t[asl]j; 48), n. [Aphetic form of OE.
   avantage, fr. F. avantage. See Advantage.]
   1. Superior or more favorable situation or opportunity; gain;
      profit; advantage. [R.]
      [1913 Webster]

            O happy vantage of a kneeling knee!   --Shak.
      [1913 Webster]

   2. A position offering a superior view of a scene or
      situation; -- used literally and figuratively; as, from
      the vantage of hindsight; also called vantage point.
      [PJC]

   3. (Tennis) The first point scored after deuce; advantage[5].
      [Brit.]
      [1913 Webster]

   Note: When the server wins this point, it is called vantage
         in; when the receiver, or striker out, wins, it is
         called vantage out.
         [1913 Webster]

   To have at vantage, to have the advantage of; to be in a
      more favorable condition than. "He had them at vantage,
      being tired and harassed with a long march." --Bacon.

   Vantage ground, superiority of state or place; the place or
      condition which gives one an advantage over another. "The
      vantage ground of truth." --Bacon.
      [1913 Webster]

            It is these things that give him his actual
            standing, and it is from this vantage ground that he
            looks around him.                     --I. Taylor.
      [1913 Webster]

WordNet (r) 3.0 (2006):

vantage
    n 1: place or situation affording some advantage (especially a
         comprehensive view or commanding perspective)
    2: the quality of having a superior or more favorable position;
       "the experience gave him the advantage over me" [syn:
       advantage, vantage] [ant: disadvantage]