  Gauging the global $B-L$ (Baryon number minus Lepton number) symmetry in the
Standard Model (SM) is well-motivated since anomaly cancellations require the
introduction of three right-handed neutrinos (RHNs) which play an essential
role in naturally generating tiny SM neutrino masses through the seesaw
mechanism. In the context of the $B-L$ extended SM, we propose a
pseudo-Goldstone boson dark matter (DM) scenario in which the imaginary
component of a complex $B-L$ Higgs field serves as the DM in the universe. The
DM relic density is determined by the SM Higgs boson mediated process, but its
elastic scattering with nucleons through the exchange of Higgs bosons is highly
suppressed due to its pseudo-Goldstone boson nature. The model is therefore
free from the constraints arising from direct DM detection experiments. We
identify regions of the model parameter space for reproducing the observed DM
density compatible with the constraints from the Large Hadron Collider and the
indirect DM searches by Fermi-LAT and MAGIC.
