pneumonia

noun

pneu·​mo·​nia nu̇-ˈmō-nyə How to pronounce pneumonia (audio)
nyu̇-
: an acute disease that is marked by inflammation of lung tissue accompanied by infiltration of alveoli and often bronchioles with white blood cells (such as neutrophils) and fibrinous exudate, is characterized by fever, chills, cough, difficulty in breathing, fatigue, chest pain, and reduced lung expansion, and is typically caused by an infectious agent (such as a bacterium, virus, or fungus) see bronchopneumonia, pneumocystis carinii pneumonia, primary atypical pneumonia compare pneumonitis

Examples of pneumonia in a Sentence

He caught pneumonia over the winter.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
In 2019, the girl developed a severe case of pneumonia, which eventually led to inflammation of the heart. Ruchi Kumar, NPR, 14 Sep. 2025 The condition led the singer to be frequently hospitalized with pneumonia and bronchitis in the final years of his life, according to Rolling Stone. Lynsey Eidell, People.com, 12 Sep. 2025 Death is usually caused by pneumonia, according to Encephalitis International. Mary Walrath-Holdridge, USA Today, 12 Sep. 2025 Kilmer died at age 65 of pneumonia, his daughter Mercedes Kilmer confirmed to the New York Times, after battling throat cancer for a number of years. Chris Gardner, HollywoodReporter, 12 Sep. 2025 See All Example Sentences for pneumonia

Word History

Etymology

New Latin, from Greek, from pneumōn lung, alteration of pleumōn — more at pulmonary

First Known Use

1603, in the meaning defined above

Time Traveler
The first known use of pneumonia was in 1603

Browse Nearby Words

Cite this Entry

“Pneumonia.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/pneumonia. Accessed 18 Sep. 2025.

Kids Definition

pneumonia

noun
pneu·​mo·​nia n(y)u̇-ˈmō-nyə How to pronounce pneumonia (audio)
: a disease of the lungs marked by inflammation, congestion, fever, cough, and difficulty in breathing and caused especially by infection

Medical Definition

pneumonia

noun
pneu·​mo·​nia n(y)u̇-ˈmō-nyə How to pronounce pneumonia (audio)
: an acute disease that is marked by inflammation of lung tissue accompanied by infiltration of alveoli and often bronchioles with white blood cells (as neutrophils) and fibrinous exudate, is characterized by fever, chills, cough, difficulty in breathing, fatigue, chest pain, and reduced lung expansion, and is typically caused by an infectious agent (as a bacterium, virus, or fungus) see bronchopneumonia, lobar pneumonia, pneumocystis carinii pneumonia, primary atypical pneumonia

More from Merriam-Webster on pneumonia

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