an automatic control system in which the output is constantly or intermittently compared with the input through feedback so that the error or difference between the two quantities can be used to bring about the desired amount of control
Origin:
< servomotor + mechanism
See servomechanism in American Heritage Dictionary 4
noun
A feedback system that consists of a sensing element, amplifier, and servomotor, used in the automatic control of a mechanical device.
A self-regulating feedback system or mechanism: “We do not need to know in detail how the minute chemical servomechanisms of the muscles operate in order to move our arms”(Harper's).