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.
Pneumococcal disease is a bacterial infection that can cause many different illnesses, including pneumonia, blood infections, meningitis, and ear and sinus infections. Michelle Marchante september 8, Miami Herald, 8 Sep. 2025 Pneumococcal disease often causes pneumonia, the leading cause of death worldwide for all children under 5, with an annual toll of about 700,000. Michal Ruprecht, NPR, 8 Sep. 2025 However, an autopsy later revealed that his cause of death was pneumonia. Ashley Hume, FOXNews.com, 7 Sep. 2025 He was first diagnosed with pneumonia before an echocardiogram revealed that his heart was causing the issue. Adam England, PEOPLE, 6 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 11 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

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!