An Etymological Dictionary of Astronomy and Astrophysics

A device for measuring or maintaining orientation. Consisting of a rotating wheel so mounted that its axis can turn freely in certain or all directions, it is
based on the principle of conservation of angular momentum. In physics this is also known as gyroscopic inertia or rigidity in space.

Etymology (EN): Gyroscope, from gyro-, → gyrate + → -scope.

Etymology (PE): Lernemâ, from ler, → gyrate, + -nemâ→ -scope; carxešnemâ, from carxeš→ rotation + -nemâ.