Meaning

• An employee or other worker with some particular function or skill.

• A spy, secret agent, or detective.

• A participant in an operation.

Meaning

• Effectual or important.

  "He's usually in a good mood — the operative word there being "usually". Today was a disaster."

• Functional, in working order.

• Having the power of acting; hence, exerting force, physical or moral; active in the production of effects.

  "an operative motive"

• Producing the appropriate or designed effect; efficacious.

  "an operative dose, rule, or penalty"

• Based upon, or consisting of, a surgical operation or operations.

  "operative surgery"