  Inelastic neutron scattering (INS) measurements of powder
D$_3(^{7}$Li)($^{193}$Ir)$_2$O$_6$ reveal low energy magnetic excitations with
a scattering cross section that is broad in $|Q|$ and consistent with a Kitaev
spin-liquid (KSL) state. The magnetic nature of the excitation spectrum is
demonstrated by longitudinally polarized neutron studies. The total magnetic
moment of 1.7(2)$\mu_B$/Ir inferred from the total magnetic scattering cross
section is consistent with the effective moment inferred from magnetic
susceptibility data and expectations for the $J_{\rm eff}=1/2$ single ion
state. The rise in the dynamic correlation function ${\cal S}(Q,\omega)$ for
$\hbar\omega<5~$meV can be described by a nearest-neighbor Kitaev model with
interaction strength $K\approx-13(5)$~meV. Exchange disorder associated with
the mixed D-Li site could play an important role in stabilizing the low $T$
quantum fluctuating state.
