Definitions
1.AdjectiveEffectual or important."He's usually in a good mood — the operative word there being "usually". Today was a disaster."
2.AdjectiveFunctional, in working order.
3.AdjectiveHaving the power of acting; hence, exerting force, physical or moral; active in the production of effects."an operative motive"
4.AdjectiveProducing the appropriate or designed effect; efficacious."an operative dose, rule, or penalty"
5.AdjectiveBased upon, or consisting of, a surgical operation or operations."operative surgery"
6.NounAn employee or other worker with some particular function or skill.
7.NounA spy, secret agent, or detective.
8.NounA participant in an operation.