What does "mononucleosis" mean?

A viral infection marked by extreme fatigue, high fever, and swollen lymph nodes.

How do you pronounce "mononucleosis"?

Pronounced //ˌmɑnoʊnukliˈoʊsɪs//.

Common synonyms include: glandular fever, infectious mononucleosis, kissing disease, mono, infectious mononucleosis, glandular fever.

//ˌmɑnoʊnukliˈoʊsɪs// noun

noun ·Rare ·Advanced level

Noun

1
A viral infection marked by extreme fatigue, high fever, and swollen lymph nodes. uncountable, usually
2
an acute disease characterized by fever and swollen lymph nodes and an abnormal increase of mononuclear leucocytes or monocytes in the bloodstream; not highly contagious; some believe it can be transmitted by kissing wordnet

"Mononucleosis is also known as the kissing disease."

From mono- + nucleus + -osis.

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.