The Collaborative International Dictionary of English v.0.48:

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.
      [1913 Webster]

   2. To control the action of, by management; as, to manipulate
      a convention of delegates; also, to manage artfully or
      fraudulently; as, to manipulate accounts, or election
      returns; to manipulate the stock market.
      [1913 Webster]