  We explore the 21-cm signal in our Universe containing inhomogeneous matter
distribution at considerably large scales. Employing Buchert's averaging
procedure in the context of a model of spacetime with multiple inhomogeneous
domains, we evaluate the effect of our model parameters on the observable 21-cm
signal brightness temperature. Our model parameters are constrained through the
Markov Chain Monte Carlo method using the Union 2.1 supernova Ia observational
data. We find that a significant dip in the brightness temperature compared to
the $\Lambda$CDM prediction could arise as an effect of the inhomogeneities
present in the Universe.
