Merriam-Webster Collegiate Dictionary - meningitis

 noun  (plural meningitides)  Etymology: New Latin  Date: 1824  1. inflammation of the meninges and especially of the pia mater and the arachnoid  2. a disease marked by inflammation of the meninges that may be either a relatively mild illness caused by a virus (as the Coxsackie virus) or a more severe life-threatening illness caused by a bacterium (as the meningococcus)  • meningitic adjective