The Collaborative International Dictionary of English v.0.48:

Operate \Op"er*ate\, v. t.
   1. To produce, as an effect; to cause.
      [1913 Webster]

            The same cause would operate a diminution of the
            value of stock.                       --A. Hamilton.
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   2. To put into, or to continue in, operation or activity; to
      work; as, to operate a machine.
      [1913 Webster] Operatic

The Collaborative International Dictionary of English v.0.48:

Operate \Op"er*ate\, v. i. [imp. & p. p. Operated; p. pr. &
   vb. n. Operating.] [L. operatus, p. p. of operari to work,
   fr. opus, operis, work, labor; akin to Skr. apas, and also to
   G. ["u]ben to exercise, OHG. uoben, Icel. [ae]fa. Cf.
   Inure, Maneuver, Ure.]
   1. To perform a work or labor; to exert power or strength,
      physical or mechanical; to act.
      [1913 Webster]

   2. To produce an appropriate physical effect; to issue in the
      result designed by nature; especially (Med.), to take
      appropriate effect on the human system.
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   3. To act or produce effect on the mind; to exert moral power
      or influence.
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            The virtues of private persons operate but on a few.
                                                  --Atterbury.
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            A plain, convincing reason operates on the mind both
            of a learned and ignorant hearer as long as they
            live.                                 --Swift.
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   4. (Surg.) To perform some manual act upon a human body in a
      methodical manner, and usually with instruments, with a
      view to restore soundness or health, as in amputation,
      lithotomy, etc.
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   5. To deal in stocks or any commodity with a view to
      speculative profits. [Brokers' Cant]
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WordNet (r) 3.0 (2006):

operate
    v 1: direct or control; projects, businesses, etc.; "She is
         running a relief operation in the Sudan" [syn: operate,
         run]
    2: perform as expected when applied; "The washing machine won't
       go unless it's plugged in"; "Does this old car still run
       well?"; "This old radio doesn't work anymore" [syn:
       function, work, operate, go, run] [ant:
       malfunction, misfunction]
    3: handle and cause to function; "do not operate machinery after
       imbibing alcohol"; "control the lever" [syn: operate,
       control]
    4: perform a movement in military or naval tactics in order to
       secure an advantage in attack or defense [syn: manoeuver,
       maneuver, manoeuvre, operate]
    5: happen; "What is going on in the minds of the people?"
    6: keep engaged; "engaged the gears" [syn: engage, mesh,
       lock, operate] [ant: disengage, withdraw]
    7: perform surgery on; "The doctors operated on the patient but
       failed to save his life" [syn: operate on, operate]