operative

IPA: ˈɑpɝʌtɪv

Effectual or important.
Functional, in working order.
Having the power of acting; hence, exerting force, physical or moral; active in the production of effects.
Producing the appropriate or designed effect; efficacious.
Based upon, or consisting of, a surgical operation or operations. [from Template:SAFESUBST: c.]

Examples of "operative" in Sentences

But, you know, her role as a top agency operative is not disputed.
In actual, main operative Pygmy co-opted by shallow, corrupt, depraved host country.
A third-party group headed by a GOP operative is out with a new Nevada ad spot encouraging Latinos in the state not to cast votes in this year's midterm elections.
Charlie Crist Jr., who, according to one McCain operative, is the other candidate — besides Jindal — who McCain is seriously considering tapping as his running mate.
Deposada, a GOP operative from the failed Bush Presidency, crossed a critical line this week by developing and placing ads urging Latino voters to stay home and not vote during this important election cycle.
Robert Deposada, a GOP operative from the failed Bush Presidency, has crossed a critical line this week by developing and placing ads urging Latino voters to stay home and not vote during this important election cycle.
"It should come as no surprise that a staunch Pelosi ally and former DCCC operative is beating down the doors of lobbyists in order to funnel millions in campaign cash so that Democrats can put more absurd ads on the air attacking Republicans as hand-maidens of the special interests."