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

That operates to produce an effect.

plural of operant

plural of operativeness

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

plural of oper

(Internet) A network operator on IRC.

(mathematics, logic) An operation on logical values that changes true to false, and false to true.

In an operative manner.

The extent to which a system or device is operable.