  We study holographic renormalization and RG flow in a strongly-coupled
Lifshitz-type theory in 2+1 dimensions with dynamical exponent z=2. The
bottom-up gravity dual we use is 3+1 dimensional Einstein gravity coupled to a
massive vector field. This model contains a marginally relevant operator around
the Lifshitz fixed point. We show how holographic renormalization works in the
presence of this marginally relevant operator without the need to introduce
explicitly cutoff-dependent counterterms. A simple closed-form expression is
found for the renormalized on-shell action. We also discuss how asymptotically
Lifshitz geometries flow to AdS in the interior due to the marginally relevant
operator. We study the behavior of the renormalized entanglement entropy and
confirm that it decreases monotonically along the Lifshitz-to-AdS RG flow.
