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.
      [1913 Webster]

   3. To act or produce effect on the mind; to exert moral power
      or influence.
      [1913 Webster]

            The virtues of private persons operate but on a few.
                                                  --Atterbury.
      [1913 Webster]

            A plain, convincing reason operates on the mind both
            of a learned and ignorant hearer as long as they
            live.                                 --Swift.
      [1913 Webster]

   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.
      [1913 Webster]

   5. To deal in stocks or any commodity with a view to
      speculative profits. [Brokers' Cant]
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

operating \operating\ adj.
   1. pr. p. of operate; as, the operating conditions of the
      oxidation pond.
      [WordNet 1.5]

   2. having an effect or influence.

   Syn: at work(predicate), in operation, operant.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

operating
    adj 1: involved in a kind of operation; "the operating
           conditions of the oxidation pond"
    2: being in effect or operation; "de facto apartheid is still
       operational even in the `new' African nations"- Leslie Marmon
       Silko; "bus service is in operation during the emergency";
       "the company had several operating divisions" [syn:
       operational, in operation(p), operating(a)]

The Free On-line Dictionary of Computing (19 January 2023):

operating

   1. operating system.

   2. operator.