Source : Webster's Revised Unabridged Dictionary (1913)

Manipulate \Ma*nip"u*late\, v. t. [imp. & p. p. {Manipulated};
   p. pr. & vb. n. {Manipulating}.] [LL. manipulatus, p. p. of
   manipulare to lead by the hand, fr. L. manipulus. See
   {Maniple}.]
   1. To treat, work, or operate with the hands, especially when
      knowledge and dexterity are required; to manage in hand
      work; to handle; as, to manipulate scientific apparatus.

   2. To control the action of, by management; as, to manipulate
      a convention of delegates; to manipulate the stock market;
      also, to manage artfully or fraudulently; as, to
      manipulate accounts, or election returns.

Manipulate \Ma*nip"u*late\, v. i.
   To use the hands in dexterous operations; to do hand work;
   specifically, to manage the apparatus or instruments used in
   scientific work, or in artistic or mechanical processes;
   also, specifically, to use the hand in mesmeric operations.

Source : WordNet®

manipulate
     v 1: influence or control shrewdly or deviously; "He manipulated
          public opinion in his favor" [syn: {pull strings}, {pull
          wires}]
     2: hold something in one's hands and move it
     3: fake or falsify; "Fudge the figures"; "cook the books";
        "falsify the data" [syn: {fudge}, {fake}, {falsify}, {cook},
         {wangle}, {misrepresent}]
     4: manipulate in a fraudulent manner; "rig prices" [syn: {rig}]
     5: control (others or oneself) or influence skillfully, usually
        to one's advantage; "She manipulates her boss"; "She is a
        very controlling mother and doesn't let her children grow
        up"; "The teacher knew how to keep the class in line";
        "she keeps in line" [syn: {keep in line}, {control}]
     6: treat manually, as with massage, for therapeutic purposed