Meningism is a derived term of meningitis.

As nouns the difference between meningism and meningitis

is that meningism is the triad of nuchal rigidity (neck stiffness), photophobia, and headache, a sign of irritation of the meninges, as seen in meningitis, subarachnoid hemorrhages, etc while meningitis is (pathology) inflammation of the meninges, characterized by headache, neck stiffness and photophobia and also fever, chills, vomiting and myalgia.