mononucleosisPronunciation: /ˌmɒnə(ʊ)njuːklɪˈəʊsɪs/Definition of mononucleosis noun [mass noun] Medicine an abnormally high proportion of monocytes in the blood, especially associated with glandular fever. mononucleosis in other Oxford dictionaries Definition of mononucleosis in the US English dictionary
