  Quantum Griffiths singularity (QGS), which is closely correlated with the
quenched disorder, is characterized by the divergence of the dynamical critical
exponent and the presence of activated scaling behavior. Typically such a
quantum phenomenon is rather rare and only observed in extremely low
temperatures. Here we report the experimental observation of a robust QGS in
nitride thin films, NbN, which survives in a rather high temperature range. The
electrical transport propertied were measured under the magnetic field up to 12
T. The field induced superconductor-metal transitions were observed with the
continuously changed transition points with the decrease of temperature. The
dynamical critical exponent based on the conventional power-law scaling reveals
a divergent trend when approaching the the low temperature limit. Moreover, the
temperature and field dependence of sheet resistance can be described by the
activated scaling analysis in the temperature region up to 1.6 K $\leq T \leq$
4.0 K. We argue that the robustness of QGS in the present system originates
from the Pauli paramagnetic effect due to the strong coupling between the
magnetic field and the spin degree of freedom.
