In a Whitehead torpedo, a compressed-air motor, for moving the rudders so as to correct deviations from the course
A relay apparatus; 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
[ 's&r-vO-"mO-t&r ] (noun.) 1889. French servo-moteur, from Latin servus slave, servant + French -o- + moteur motor, from Latin motor one that moves; more at MOTOR.