  We report experimental evidences for the observation of the superconducting
amplitude mode, so-called `Higgs' mode in the charge density wave
superconductor 2H-NbSe2 using Raman scattering. By comparing 2H-NbSe2 and its
iso-structural partner 2H-NbS2 which shows superconductivity but lacks the
charge density wave order, we demonstrate that the superconducting mode in
2H-NbSe2 owes its spectral weight to the presence of the coexisting charge
density wave order. In addition, temperature dependent measurements in 2H-NbSe2
show a full spectral weight transfer from the charge density wave mode to the
superconducting mode upon entering the superconducting phase. Both observations
are fully consistent with a superconducting amplitude mode or Higgs mode.
