  We report studies of the frequency dependent shear modulus,
$G^*(\omega)=G'(\omega)+iG''(\omega)$, of the liquid crystal octylcyanobiphenyl
(8CB) confined in a colloidal aerosil gel. With the onset of smectic order,
$G'$ grows approximately linearly with decreasing temperature, reaching values
that exceed by more than three orders of magnitude the values for pure 8CB. The
modulus at low temperatures possesses a power-law component, $G^*(\omega) \sim
\omega^\alpha$, with exponent $\alpha$ that approaches zero with increasing gel
density. The amplitude of $G'$ and its variation with temperature and gel
density indicate that the low temperature response is dominated by a dense
population of defects in the smectic. In contrast, when the 8CB is isotropic or
nematic, the modulus is controlled by the elastic behavior of the colloidal
gel.
