mononucleosis

noun

mono·​nu·​cle·​o·​sis ˌmä-nə-ˌnü-klē-ˈō-səs 

-ˌnyü-

: an abnormal increase of mononuclear white blood cells in the blood

specifically : infectious mononucleosis

Examples of mononucleosis in a Sentence

Recent Examples on the Web

Hall, one of four returners, contracted mononucleosis in the preseason. —Brian Hamilton, The Athletic, 14 Feb. 2025

Schaefer’s start to his 2024-25 OHL season was delayed until late October due to a bout with mononucleosis. —Carol Schram, Forbes, 14 Jan. 2025

Risk factors include having low vitamin D levels, smoking cigarettes, and having Epstein-Barr virus (EBV), which causes mononucleosis (mono). —Brandi Jones, Msn-Ed, Rn-Bc, Health, 24 Sep. 2024

Smith missed five games in the middle of his rookie season with mononucleosis. —Brad Biggs, Chicago Tribune, 18 Aug. 2024

Word History

Etymology

New Latin, from International Scientific Vocabulary mononuclear + New Latin -osis

First Known Use

1902, in the meaning defined above

Phrases Containing mononucleosis

• infectious mononucleosis

Medical Definition

mononucleosis

noun

mono·​nu·​cle·​o·​sis -ˌn(y)ü-klē-ˈō-səs 

: an abnormal increase of mononuclear white blood cells in the blood

specifically : infectious mononucleosis