Source : Webster's Revised Unabridged Dictionary (1913)

Overreach \O`ver*reach"\, v. t. [imp. & p. p. {Overreached},
   ({Overraught}, obs.); p. pr. & vb. n. {Overreaching}.]
   1. To reach above or beyond in any direction.

   2. To deceive, or get the better of, by artifice or cunning;
      to outwit; to cheat. --Shak.

Source : WordNet®

overreaching
     adj : revealing excessive self-confidence; reaching for the
           heights; "vaulting ambition" [syn: {vaulting}]