  We study the shear viscosity in an effective hydrodynamic theory and
holographic model where the translational symmetry is broken by massless scalar
fields. We identify the shear viscosity, $\eta$, from the coefficient of the
shear tensor in the modified constitutive relation, constructed from
thermodynamic quantities, fluid velocity and the scalar fields, which break the
translational symmetry explicitly. Our construction of constitutive relation is
inspired by those derived from the fluid/gravity correspondence in the weakly
disordered limit $m/T \ll 1$. We show that the shear viscosity from the
constitutive relation deviates from the one obtained from the usual expression,
$\eta^\star = -\lim_{\omega\to 0}(1/\omega) \text{Im}
G^{R}_{T^{xy}T^{xy}}(\omega,k=0)$, even at the leading order in disorder
strength. In a simple holographic model with broken translational symmetry, we
show that both $\eta/s$ and ${\eta}^\star/s$ violate the bound of
viscosity-entropy ratio for arbitrary disorder strength.
