Noah Webster's New International Dictionary of the English Language

1. (a.) Being in effect; acting; most important; surgical; exerting force, physical or moral; active in the production of effects; as, an operative motive.

2. (a.) Producing the appropriate or designed effect; efficacious; as, an operative dose, rule, or penalty.

3. (a.) Based upon, or consisting of, an operation or operations; as, operative surgery.

4. (n.) A skilled worker; an artisan; esp., one who operates a machine in a mill or manufactory.