Operant
Part of speech: adjective
Definition: That operates to produce an effect
Part of speech: noun
Definition: An operative person or thing. A class of behavior that produces consequences by operating (i.e., acting) upon the environment.
Operative
Part of speech: noun
Definition: An employee or other worker with some particular function or skill.A spy, secret agent, or detective.
Part of speech: adjective
Definition: Effectual or important.Functional, in working order.