influenza

noun
in·​flu·​en·​za | \ ˌin-(ˌ)flü-ˈen-zə How to pronounce influenza (audio) \

Definition of influenza

1a : an acute, highly contagious, respiratory disease caused by any of three orthomyxoviruses:
(1) or influenza A : moderate to severe influenza that in humans is marked especially by sudden onset, fever, sore throat, fatigue, muscle aches, inflammation of the respiratory mucous membranes, and cough, that has numerous variants caused by subtypes (such as H1N1, H2N2, or H3N2) of an orthomyxovirus (species Influenza A virus of the genus Influenzavirus A) infecting humans and various animals (such as birds or pigs), and that may occur in seasonal epidemics or sometimes pandemics following mutation in the causative virus
(2) or influenza B : influenza with less severe symptoms that is caused by an orthomyxovirus (species Influenza B virus of the genus Influenzavirus B) infecting only humans and especially children and that may occur in seasonal epidemics but not pandemics
(3) or influenza C : mild influenza that is often asymptomatic, is caused by an orthomyxovirus (species Influenza C virus of the genus Influenzavirus C) infecting only humans, and does not occur in epidemics or pandemics
b : any of various human respiratory infections of undetermined cause not used technically
2 : any of various virus diseases of domestic animals marked especially by fever, respiratory symptoms, and inflammation of mucous membranes

Note: All types of influenza are commonly called "the flu."

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Other Words from influenza

influenzal \ ˌin-​(ˌ)flü-​ˈen-​zəl How to pronounce influenzal (audio) \ adjective
influenzal pneumonia influenzal symptoms

Examples of influenza in a Sentence

Recent Examples on the Web The influenza pandemic of 1918, like this year’s COVID-19 outbreak, coincided with a time of social unrest. Dave Birkett, Detroit Free Press, "How COVID-19 will change sports as we know them: 'The virus is shaping the sports world'," 11 Sep. 2020 The process will be run by the CDC, which for decades has overseen vaccine distribution in the United States and ran the last national vaccination effort during the 2009 H1N1 influenza pandemic. Elinor Aspegren, USA TODAY, "Coronavirus live updates: Trump asks reporter to remove mask; French Open to allow spectators; US nears 190K deaths," 8 Sep. 2020 As India races towards the 4-million mark of Covid-19 positive cases, there are lessons its government can learn from the Spanish influenza pandemic almost a century ago. Manavi Kapur, Quartz India, "The British Raj’s Spanish flu response has a lesson for India’s Covid-19 battle," 2 Sep. 2020 When covid-19 vaccines become available, health providers will need to track where and when patients receive their vaccines, said Moore, the medical director of Tennessee's immunization plan during the H1N1 influenza pandemic in 2009 and 2010. Arkansas Online, "Health officials worry nation not ready for covid-19 vaccine," 2 Sep. 2020 According to Kyodo News, Japanese museums’ efforts to collect artifacts related to the Covid-19 pandemic stem from a shortage of documentation dated to the 1918–1919 influenza pandemic. Theresa Machemer, Smithsonian Magazine, "How a Japanese Museum Is Documenting Life During Covid-19," 25 Aug. 2020 During the influenza pandemic in 1918, even though the world was a very different place, the discussion was just as heated. Theresa Waldrop, CNN, "Here's what happened when students went to school during the 1918 pandemic," 19 Aug. 2020 In all the places that Natarajan has looked at in this context, unrest against colonial governments predated the influenza pandemic. oregonlive, "Did coronavirus lay the groundwork for nationwide protests against systemic racism?," 18 Aug. 2020 Like much of the Western world, Britain had prepared for an influenza pandemic, whereas places that were hit early—Hong Kong, South Korea, Singapore, Taiwan—had readied themselves for the type of respiratory illness that COVID-19 proved to be. Tom Mctague, The Atlantic, "How The Pandemic Revealed Britain’s National Illness," 12 Aug. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'influenza.' 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 influenza

1743, in the meaning defined at sense 1a

History and Etymology for influenza

Italian, literally, influence, from Medieval Latin influentia; from the belief that epidemics were due to the influence of the stars

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Time Traveler for influenza

Time Traveler

The first known use of influenza was in 1743

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Statistics for influenza

Last Updated

25 Sep 2020

Cite this Entry

“Influenza.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/influenza. Accessed 1 Oct. 2020.

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More Definitions for influenza

influenza

noun
How to pronounce influenza (audio)

English Language Learners Definition of influenza

medical : a common illness that is caused by a virus and that causes fever, weakness, severe aches and pains, and breathing problems

influenza

noun
in·​flu·​en·​za | \ ˌin-flü-ˈen-zə How to pronounce influenza (audio) \

Kids Definition of influenza

: a very contagious virus disease like a severe cold with fever

influenza

noun
in·​flu·​en·​za | \ ˌin-(ˌ)flü-ˈen-zə How to pronounce influenza (audio) \

Medical Definition of influenza

1a : an acute, highly contagious, respiratory disease caused by any of three orthomyxoviruses:
(1) or influenza A : moderate to severe influenza that in humans is marked especially by sudden onset, fever, sore throat, fatigue, muscle aches, inflammation of the respiratory mucous membranes, and cough, is caused by any of several subtypes (such as H1N1, H2N2, or H3N2) of an orthomyxovirus (species Influenza A virus of the genus Influenzavirus A) infecting humans and various animals (such as birds or pigs), and may occur in seasonal epidemics or sometimes pandemics following mutation of the causative virus — see asian flu, avian influenza, bird flu, hong kong flu, spanish flu, swine flu, swine influenza
(2) or influenza B : influenza with less severe symptoms that is caused by an orthomyxovirus (species Influenza B virus of the genus Influenzavirus B) infecting only humans and especially children and that may occur in seasonal epidemics but not pandemics
(3) or influenza C : mild influenza that is often asymptomatic, is caused by an orthomyxovirus (species Influenza C virus of the genus Influenzavirus C) infecting only humans, and does not occur in epidemics or pandemics
b : any human respiratory infection of undetermined cause not used technically
2 : any of various viral diseases of domestic animals (as shipping fever of horses) marked especially by fever, respiratory symptoms, and inflammation of mucous membranes

Note: All types of influenza are commonly called "the flu."

Other Words from influenza

influenzal \ -​zəl How to pronounce influenzal (audio) \ adjective
influenzal pneumonia influenzal symptoms

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More from Merriam-Webster on influenza

Nglish: Translation of influenza for Spanish Speakers

Britannica English: Translation of influenza for Arabic Speakers

Britannica.com: Encyclopedia article about influenza

Comments on influenza

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