an acute disease, esp. of young people, characterized by fever, swollen lymph nodes, sore throat, and abnormalities of the lymphocytes: it is caused by the Epstein-Barr virus
See infectious mononucleosis in American Heritage Dictionary 4
noun
A common, acute, infectious disease, usually affecting young people, caused by Epstein-Barr virus and characterized by fever, swollen lymph nodes, sore throat, and lymphocyte abnormalities. Also called glandular fever.