  We report the time and temperature dependent response of thermopower in the
non-magnetic perovskite oxide NdNiO$_3$. We find that on cooling below the
metal-insulator transition temperature the system evolves into a phase
separated state which consists of supercooled metallic and insulating phases.
This phase separated state exhibits out of equilibrium features such as cooling
rate dependence and time dependence. The existence of these dynamical features
is attributed to the transformation of supercooled metallic phases to the
insulating state. On cooling a small fraction of supercooled phases gets
kinetically arrested in a glassy state and these supercooled phases remain in
that state down to low temperature. In the heating cycle the arrested states
dearrest above 150 K and this results in the reappearance of time dependent
features.
