actuator
n. countable C1 Advanced US //ˈæktjuˌeɪtɝ// UK //ˈæktʃuːˌeɪtɐ// ac·tu·a·tor
n. a part of a machine that moves or controls something else. It turns energy, like electricity or air pressure, into physical movement.
n. a mechanical device for moving or controlling a system. It converts an input signal into some kind of motion or physical action, typically using energy from a source such as electricity, hydraulics, or pneumatics.
The robot uses a small actuator to move its arm.
In modern cars, the fuel injection system relies on a precise actuator to open the valve at the right time.
The engineering team replaced the hydraulic actuator with a more efficient electric version to reduce the overall weight and improve the vehicle's fuel economy.
From actuate + -or. First attested in 1652.