Source : Webster's Revised Unabridged Dictionary (1913)

Whither \Whith"er\, adv. [OE. whider. AS. hwider; akin to E.
   where, who; cf. Goth. hvadr[=e] whither. See {Who}, and cf.
   {Hither}, {Thither}.]
   1. To what place; -- used interrogatively; as, whither goest
      thou? ``Whider may I flee?'' --Chaucer.

            Sir Valentine, whither away so fast?  --Shak.

   2. To what or which place; -- used relatively.

            That no man should know . . . whither that he went.
                                                  --Chaucer.

            We came unto the land whither thou sentest us.
                                                  --Num. xiii.
                                                  27.

   3. To what point, degree, end, conclusion, or design;
      whereunto; whereto; -- used in a sense not physical.

            Nor have I . . . whither to appeal.   --Milton.

   {Any whither}, to any place; anywhere. [Obs.] ``Any whither,
      in hope of life eternal.'' --Jer. Taylor.

   {No whither}, to no place; nowhere. [Obs.] --2 Kings v. 25.

   Syn: Where.

   Usage: {Whither}, {Where}. Whither properly implies motion to
          place, and where rest in a place. Whither is now,
          however, to a great extent, obsolete, except in
          poetry, or in compositions of a grave and serious
          character and in language where precision is required.
          Where has taken its place, as in the question, ``Where
          are you going?''

Source : WordNet®

whither
     adv : to what place; "whither go you?"