noun
: the axis about which a free rigid body can rotate in equilibrium being in general the axis of greatest moment of inertia through the center of mass — compare principal axis
noun
: the axis about which a free rigid body can rotate in equilibrium being in general the axis of greatest moment of inertia through the center of mass — compare principal axis
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012