The general theory of far-infrared absorption of diatomic molecules in rare-gas fluids reported in Paper I is applied to the case of the CO-Ar system. The experimental absorption profiles of CO in Ar at three different densities (low-density gas, high-density gas, and liquid) are theoretically reproduced by considering the permanent dipole contribution and the four leading electrostatic multipole-induced dipole contributions. From these results an estimation of the quadrupole, theta, octupole, Omega and hexadecapole, Phi, moments of CO is given.