controller

One who controls something.

The great controller of our fate / Deigned to be man, and lived in low estate.

Any electric or mechanical device for controlling a circuit or system.

Nothing more can be squeezed out of the motive power unit once the master controller has been moved to full on.

The chief accounting officer which audits, and manages the financial affairs of a company or government; a comptroller.

A mechanism that controls or regulates the operation of a machine, especially a peripheral device in a computer.

A hardware device designed to allow the user to play video games.

I'm collecting player's names for a school project. You know, players just like you! That's right, you--the one holding the controller. Would you register your name, please?