Rotational motions in molecular fluids may exhibit a coherence arising from collision-free propagation or from highly correlated collisions. Information on both of these behaviors are derived from the analysis of orientational and angular momentum relaxation. In the present study, the rotating body is taken to be a hard ellipsoid, immersed in a hard sphere fluid, and its dynamics are analyzed within a framework of kinetic theory. When the fluid bath is dilute, collisions are regarded as uncorrelated events and orientational relaxation has elements of the Fokker-Planck and Gordon diffusion models. When the correlated collisions are dominant, the rotational dynamics are frustrated. In this limit the rotational diffusion coefficient vanishes, the hard sphere shear viscosity diverges and their product is well behaved and yields a relationship in close accord to the Stokes-Einstein-Debye relation.