regulator

One that regulates, as.

The mechanism in a watch by which its speed is governed.

A highly accurate clock used as a standard for timing other clocks.

A device used to maintain uniform speed in a machine; a governor.

A device used to control the flow of gases, liquids, or electric current.

One, such as the member of a governmental regulatory agency, that ensures compliance with laws, regulations, and established rules.

A substance that affects the amount of product or the progress of a biochemical reaction or process.

One who or that which regulates.