[′rāt ¦int·ə‚grād·iŋ ‚jī·rə‚skōp] (mechanical engineering) A single-degree-of-freedom gyro having primarily viscous restraint of its spin axis about the output axis; an output signal is produced by gimbal angular displacement, relative to the base, which is proportional to the integral of the angular rate of the base about the input axis.