controller
n. countablen. a piece of equipment used to operate a machine or play a game. You use it to tell a device what to do, like moving a character on a screen.
n. a device or person that directs or regulates the operation of a system or machine. Often refers to a handheld input device for electronic systems or a professional responsible for monitoring traffic or finances.
I need a new controller for my game console.
The air traffic controller guided the plane safely to the runway during the heavy storm.
Engineers installed a sophisticated logic controller to automate the factory's assembly line, significantly reducing the margin for human error in the production cycle.
From Middle English countreroller, from Anglo-Norman contreroulour and Middle French contreroleur (French contrôleur), from Medieval Latin contrārotulātor, from *contrārotulāre (from which control). Doublet of comptroller. By surface analysis, control + -er.
Commonly used in the context of gaming (input device), aviation (air traffic), or corporate finance (financial officer).