1. An apparatus consisting of a rotating wheel so mounted that its axis can turn freely in certain or all directions, and capable of maintaining the same absolute direction in space in spite of movements of the mountings and surrounding parts.
2. Used to maintain equilibrium, to determine direction, etc.

A gyroscope in which an electrostatic field supports a central beryllium ball (metal with a high ratio of strength to weight or the lightest structural metal known) that is surrounded by six electrodes in a vacuum inside a ceramic envelope.

A gyroscope is a mechanical or an optical tool which is used to maintain orientation during motion.

A mechanical gyroscope consists of a rapidly spinning wheel set in a framework that permits it to tilt freely in any direction or to rotate around any axis.

An optical gyroscope, laser or fiber, measures the interference pattern generated by two light beams, traveling in opposite directions inside a mirrored ring or fiber loop, in order to detect very small changes in motion.

Gyroscopes are utilized in compasses, in automatic pilots on ships and aircraft, in the steering mechanisms of torpedoes, in antiroll equipment on large ships, and in inertial guidance systems or resistance of objects to any changes in their status of motion.