meningoencephalitisPronunciation: /mɪˈŋɪŋgəʊɛnˌsɛfəˈlʌɪtɪs, -ˈnɪndʒəʊ-, -ˌkɛf-/Definition of meningoencephalitis noun [mass noun] Medicine inflammation of the membranes of the brain and the adjoining cerebral tissue. meningoencephalitis in other Oxford dictionaries Definition of meningoencephalitis in the US English dictionary