pneumonia

noun

pneu·​mo·​nia nu̇-ˈmō-nyə 

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

Rather, their lawsuit suggested that the incident caused bacteria to get into Cardenas’ lungs, resulting in pneumonia and later sepsis that overwhelmed his body’s organs. —Jakob Rodgers, Mercury News, 14 Jan. 2026

Forsythe was diagnosed with colon cancer in 2006 and died from complications of pneumonia on April 1, 2010, at his home in Santa Ynez, Calif. —Nicole Briese, PEOPLE, 13 Jan. 2026

Most kids will recover from measles, but infection can lead to dangerous complications such as pneumonia, blindness, brain swelling, and death. —Dan Raby, CBS News, 12 Jan. 2026

Third, Xofluza is better at heading off serious post-flu complications such as pneumonia or myocarditis. —Sarah Zhang, The Atlantic, 12 Jan. 2026

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

Phrases Containing pneumonia

• double pneumonia
• Pneumocystis carinii pneumonia
• primary atypical pneumonia
• walking pneumonia

Rhymes for pneumonia

• ammonia
• begonia
• bronchopneumonia
• pleuropneumonia

Kids Definition

pneumonia

noun

pneu·​mo·​nia n(y)u̇-ˈmō-nyə 

: 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 

: 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