|gyroscope or gyrostat (ˈdʒaɪrəˌskəʊp)|
|Sometimes shortened to: gyro a device containing a disc rotating on an axis that can turn freely in any direction so that the disc resists the action of an applied couple and tends to maintain the same orientation in space irrespective of the movement of the surrounding structure|
|gyrostat or gyrostat|
|gyroscopic or gyrostat|
|gyro'scopically or gyrostat|
|gyro'scopics or gyrostat|
|gyroscope (jī'rə-skōp') Pronunciation Key
An instrument consisting of a heavy disk or wheel spun rapidly about an axis like a top. The angular momentum of the disk causes it to resist changes in the direction of its axis of rotation, due to the principle of conservation of angular momentum. Because of the gyroscope's tendency to remain oriented in one direction, it is used as a stabilizing device in missiles, as well as in the navigation and piloting systems of airplanes, ships, rockets, and other vehicles.