glioblastomaPronunciation: /ˌglʌɪə(ʊ)blaˈstəʊmə/Definition of glioblastoma noun (plural glioblastomas or glioblastomata /-mətə/) Medicine a highly invasive glioma in the brain. glioblastoma in other Oxford dictionaries Definition of glioblastoma in the US English dictionary