Source : Webster's Revised Unabridged Dictionary (1913)

Leverage \Lev"er*age\ (l[e^]v"[~e]r*[asl]j or
   l[=e]"v[~e]r*[asl]j), n.
   The action of a lever; mechanical advantage gained by the
   lever.

   {Leverage of a couple} (Mech.), the perpendicular distance
      between the lines of action of two forces which act in
      parallel and opposite directions.

   {Leverage of a force}, the perpendicular distance from the
      line in which a force acts upon a body to a point about
      which the body may be supposed to turn.

Source : WordNet®

leverage
     n 1: the mechanical advantage gained by being in a position to
          use a lever [syn: {purchase}]
     2: strategic advantage; power to act effectively; "relatively
        small groups can sometimes exert immense political
        leverage"
     3: investing with borrowed money as a way to amplify potential
        gains (at the risk of greater losses) [syn: {leveraging}]
     v 1: supplement with leverage; "leverage the money that is
          already available"
     2: provide with leverage; "We need to leverage this company"