mesotheliomaPronunciation: /ˌmɛsə(ʊ)ˌθiːlɪˈəʊmə, ˌmɛz-, ˌmiːs-, ˌmiːz-/Definition of mesothelioma noun [mass noun] Medicine a cancer of mesothelial tissue, associated especially with exposure to asbestos. mesothelioma in other Oxford dictionaries Definition of mesothelioma in the US English dictionary