Fr.: période de précession
The interval with which a rotating body precesses. The precession period of the Earth is 25,770 years. For a → spinning top it is given by: Tp = (4π2I)/(mgrTs), where I is the → moment of inertia, m the mass of the top, g gravity, r the distance between the center of mass and the contact point, and Ts is the spinning period of the top.