operant

adj. working, in operation; pertaining to spontaneous behavior (Psychology)

n. operator; something which operates; behavior that's performed in a spontaneous manner without any reinforcement (Psychology)

"Operant" redirects here. For the meaning of operant, see . Operant conditioning is the use of consequences to modify the occurrence and form of behavior. Operant conditioning is distinguished from Pavlovian conditioning in that operant conditioning deals with the modification of "voluntary behavior" through the use of consequences, while Pavlovian conditioning deals with the conditioning of behavior so that it occurs under new antecedent conditions.
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Adjective
1. having influence or producing an effect; "many emotional determinants at work"; "an operant conscience"
(synonym) at work(p)
(similar) operative

v. operate, carry out, run, effectuate

(n.)
An operative person or thing.
  

(a.)
Operative.