Gyrostat

Gy″ro‐stat (jī″rō̍‐stăt), n. [Gr. γυ̑ροσ ring, circle + ιστἅναι to cause to stand.] (Physics) A modification of the gyroscope, consisting essentially of a fly wheel fixed inside a rigid case to which is attached a thin flange of metal for supporting the instrument. It is used in studying the dynamics of rotating bodies.