gyroscope Meaning, Definition & Usage

  1. noun rotating mechanism in the form of a universally mounted spinning wheel that offers resistance to turns in any direction
    gyro.

WordNet

Gy"ro*scope noun
Etymology
Gr. ring, circle + -scope.
Definitions
  1. A rotating wheel, mounted in a ring or rings, for illustrating the dynamics of rotating bodies, the composition of rotations, etc. It was devised by Professor W. R. Johnson, in 1832, by whom it was called the rotascope.
  2. A form of the above apparatus, invented by M. Foucault, mounted so delicately as to render visible the rotation of the earth, through the tendency of the rotating wheel to preserve a constant plane of rotation, independently of the earth's motion.

Webster 1913