leptomeningitis

noun
lep·​to·​men·​in·​gi·​tis | \ -ˌmen-ən-ˈjīt-əs How to pronounce leptomeningitis (audio) \
plural leptomeningitides\ -​ˈjit-​ə-​ˌdēz How to pronounce leptomeningitides (audio) \

Medical Definition of leptomeningitis

: inflammation of the pia mater and the arachnoid membrane