SERVOMOTORS
Noun
servomotors
plural of servomotor
Source: Wiktionary
SERVOMOTOR
Ser`vo-mo"tor, n. [Sometimes erroneously spelt serro-motor.] [F.
servo-moteur. See Serf; Motor.] (Mach.)
Definition: A relay apparatus; specif.:
(a) An auxiliary motor, regulated by a hand lever, for quickly and
easily moving the reversing gear of a large marine engine into any
desired position indicated by that of the hand lever, which controls
the valve of the motor.
(b) In a Whitehead torpedo, a compressed-air motor, for moving the
rudders so as to correct deviations from the course.
Source: Webster’s Unabridged Dictionary 1913 Edition