Effectual or important. / Functional, in working order. / Having the power of acting; hence, exerting force, physical or moral; active in the production of effects.

An employee or other worker with some particular function or skill. / A spy, secret agent, or detective. / A participant in an operation.

plural of operative

In an operative manner.

plural of operativeness

(uncountable) The state or quality of being operative. / (countable) The result or product of being operative.

One who operates. / A telecommunications facilitator whose job is to establish temporary network connections.

The method by which a device performs its function. / The method or practice by which actions are done. / The act or process of operating; agency; the exertion of power, physical, mechanical, or moral.

That operates to produce an effect.

An operative person or thing. / (psychology) Any of a class of behaviors that produce consequences by operating (i.e., acting) upon the environment.