  We consider the entropy associated with the large-scale structure of the
Universe in the linear regime, where the Universe can be described by a
perturbed Friedmann-Lema\^itre spacetime. In particular, we compare two
different definitions proposed in the literature for the entropy using a
spatial averaging prescription. For one definition, the entropy of the
large-scale structure for a given comoving volume always grows with time, both
for a CDM and a $\Lambda$CDM model. In particular, while it diverges for a CDM
model, it saturates to a constant value in the presence of a cosmological
constant. The use of a light-cone averaging prescription in the context of the
evaluation of the entropy is also discussed.
