meningitis
noun(men-in-gi-tis)
inflammation of the meninges and especially of the pia mater and arachnoid; specifically : a disease marked by inflammation of the meninges that is either a relatively mild illness caused by a virus (such as various Coxsackieviruses) or a more severe usually life-threatening illness caused by a bacterium (especially the meningococcus, Neisseria meningitides, or the serotype designated B of Haemophilus influenzae)