Operative /(?)/

Op·er·a·tive

Operative

a.
  1. Having the power of acting; hence, exerting force, physical or moral; active in the production of effects; as, an operative motive; operative laws.
    It holds in all operative principles.
  2. Producing the appropriate or designed effect; efficacious; effective; as, an operative dose, rule, or penalty.
  3. Based upon, or consisting of, an operation or operations; as, operative surgery. (Surg.)

Operative

n.
  1. A skilled worker; an artisan; esp., one who operates a machine in a mill or manufactory.
  2. One who acts as an agent of another, especially a detective or spy.