[ mon-uh-noo-klee-oh-sis, -nyoo- ]
/ ˌmɒn əˌnu kliˈoʊ sɪs, -ˌnyu- /
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noun Pathology.
the presence of an abnormally large number of mononuclear leukocytes, or monocytes, in the blood.
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Origin of mononucleosis

First recorded in 1915–20; mononucle(ar) + -osis
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use mononucleosis in a sentence

British Dictionary definitions for mononucleosis

/ (ˌmɒnəʊˌnjuːklɪˈəʊsɪs) /

pathol the presence of a large number of monocytes in the blood
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for mononucleosis

[ mŏn′ō-nōō′klē-ōsĭs ]

A common infectious disease usually affecting young people, caused by the Epstein-Barr virus and characterized by fever, sore throat, swollen lymph nodes, and fatigue. The symptoms may last for several weeks.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for mononucleosis

[ (mon-uh-nooh-klee-oh-sis) ]

An acute and infectious disease caused by a virus; its symptoms include fever, swelling of the lymph nodes, and general exhaustion. Mononucleosis gets its name from the kind of white blood cell (monocyte) that increases in number in the blood of persons who have the disease. There is no specific treatment, but sufferers usually recover within a few weeks.

notes for mononucleosis

Mononucleosis is sometimes called the “kissing disease,” because at one time the virus was thought to be transmitted by kissing. The virus can be found in the saliva of those who have the disease, so there may be some truth in the belief.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.