ˈjīrəˌskōp noun
Etymology: French, from gyro- gyr- + -scope
1. : a wheel or disk mounted to spin rapidly about an axis and also free to rotate about one or both of two axes perpendicular to each other and to the axis of spin so that a rotation of one of the two mutually perpendicular axes results from application of torque to the other when the wheel is spinning, the entire apparatus offering considerable opposition depending on the angular momentum to any torque that would change the direction of the axis of spin
2. : something resembling a gyroscope : balance wheel 2
systematic retirement programs can thus serve as a sort of economic gyroscope — New Republic