The Collaborative International Dictionary of English v.0.48:

Too \Too\, adv. [The same word as to, prep. See To.]
   [1913 Webster]
   1. Over; more than enough; -- noting excess; as, a thing is
      too long, too short, or too wide; too high; too many; too
      much.
      [1913 Webster]

            His will, too strong to bend, too proud to learn.
                                                  --Cowley.
      [1913 Webster]

   2. Likewise; also; in addition.
      [1913 Webster]

            An honest courtier, yet a patriot too. --Pope.
      [1913 Webster]

            Let those eyes that view
            The daring crime, behold the vengeance too. --Pope.
      [1913 Webster]

   Too too, a duplication used to signify great excess.
      [1913 Webster]

            O that this too too solid flesh would melt. --Shak.
      [1913 Webster]

            Such is not Charles his too too active age.
                                                  --Dryden.
      [1913 Webster]

   Syn: Also; likewise. See Also.
        [1913 Webster]

WordNet (r) 3.0 (2006):

too
    adv 1: to a degree exceeding normal or proper limits; "too big"
           [syn: excessively, overly, to a fault, too]
    2: in addition; "he has a Mercedes, too" [syn: besides, too,
       also, likewise, as well]