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

Large respiratory droplets containing pathogens like influenza can travel up to 6 feet when a sick person coughs or sneezes, according to the CDC. Colleen Stinchcombe, SELF, "Here’s How Far Germs Spread Through Sneezing and Coughing," 13 Feb. 2019 Symptoms of the keto flu are very similar to the influenza virus, including nausea, fatigue, vomiting and diarrhea. Karla Walsh, Woman's Day, "What Is the Keto Diet, Exactly?," 27 Dec. 2018 The needle-free FluMist influenza vaccine is coming back to the U.S. after two years off the market, promising a less painful way for people to inoculate themselves against the infectious disease. David Meyer, Fortune, "Next Flu Season You'll Be Able to Get Your Shot Without a Needle," 22 Feb. 2018 There are several different formulations of influenza vaccine. NBC News, "FluMist nasal flu vaccine can come back, vaccine advisers say," 21 Feb. 2018 The flu is more contagious than the common cold and is caused by influenza viruses. Craig Hlavaty, Houston Chronicle, "Is it just a cold or do you have the flu? Experts note the differences," 12 Jan. 2018 Medical examiners say the boy, Felipe Gomez Alonzo, tested positive for influenza. Amanda Sakuma, Vox, "Trump is using the deaths of two migrant children to push for his border wall," 29 Dec. 2018 In the current influenza season, the CDC has recorded 183 children who died from flu. Cathleen O'grady, Ars Technica, "A look at the virus behind seven deaths at a New Jersey facility," 25 Oct. 2018 Despite the medical advancements and innovations of the past 100 years, the world remains unprepared for when, not if, the next influenza pandemic emerges. Sy Mukherjee, Fortune, "Commentary: A $12 Million Innovation Prize for a Universal Flu Vaccine," 30 Apr. 2018

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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Dictionary Entries near influenza

influencive

influent

influential

influenza

influx

influxion

info

Statistics for influenza

Last Updated

10 Mar 2019

Look-up Popularity

Time Traveler for influenza

The first known use of influenza was in 1743

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More Definitions for influenza

influenza

noun

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

Spanish Central: Translation of influenza

Nglish: Translation of influenza for Spanish Speakers

Britannica English: Translation of influenza for Arabic Speakers

Britannica.com: Encyclopedia article about influenza

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