mono·​nu·​cle·​o·​sis | \ ˌmä-nə-ˌnü-klē-ˈō-səs How to pronounce mononucleosis (audio) , -ˌnyü-\

Definition of mononucleosis

: 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

He was shut down last summer after being diagnosed with a severe case of mononucleosis just days after the draft. Ryan Divish, The Seattle Times, "Names to watch: Breaking down the Mariners’ Top 15 prospects for 2019," 27 Mar. 2019 This combination of symptoms could also indicate an infection like shingles, mononucleosis, or even measles, according to the AAD. Korin Miller, SELF, "9 Questions That Will Help You Decode That Skin Rash," 22 Mar. 2019 But with Pete Nance sidelined indefinitely because of mononucleosis, Falzon came through in a big way. Andrew Seligman, The Seattle Times, "Falzon scores 21, Northwestern beats Indiana 73-66," 22 Jan. 2019 The Tigers will be without freshman closer Cody Greenhill due to mononucleosis, and left-handed reliever Andrew Mitchell could be sidelined after undergoing an MRI on Thursday due to forearm tightness. Tom Green,, "No. 13 Auburn baseball ready for tough SEC slate, starting with No. 10 Texas A&M," 16 Mar. 2018 But Howell’s fierce attitude was no match for battles with appendicitis and mononucleosis that affected him during the past school year. Dave Melton, Post-Tribune, "Mr. Happy Go Lucky: Metea Valley grad Christian Howell keeps it loose and throws strikes for Northwest Indiana Oilmen," 14 July 2018 Auburn closer Cody Greenhill inching closer to return to bullpen after bout with mononucleosisBullpen help could soon be on the way for No. Creg Stephenson,, "Johnny Manziel to participate in Texas A&M Pro Day on Tuesday," 26 Mar. 2018 Symptoms of mononucleosis include a sore throat, enlarged tonsils, laryngitis, swollen lymph nodes in the neck or armpits, fever, head and body aches. New York Times, "My Daughter Has Mono. Is the Whole Family at Risk?," 29 June 2018 Early assessment: Got off to a great start but then missed about two months because of mononucleosis. Helene St. James, Detroit Free Press, "Detroit Red Wings 2017 NHL draft: Michael Rasmussen looks promising," 16 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'mononucleosis.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of mononucleosis

1907, in the meaning defined above

History and Etymology for mononucleosis

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

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The first known use of mononucleosis was in 1907

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English Language Learners Definition of mononucleosis

medical : a disease that makes people very tired and weak for a long time


mono·​nu·​cle·​o·​sis | \ -ˌn(y)ü-klē-ˈō-səs How to pronounce mononucleosis (audio) \

Medical Definition of mononucleosis

: an abnormal increase of mononuclear white blood cells in the blood specifically : infectious mononucleosis

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to make a temporary encampment

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