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

The virus can cause brain swelling, pneumonia or death, and babies and young kids are especially vulnerable. —Eleanor Nash, Kansas City Star, 3 Mar. 2026

Possible complications can include croup, pneumonia, asthma attacks, middle ear infections, bronchiolitis and fever, the CDC said. —Don Sweeney, Sacbee.com, 3 Mar. 2026

The child had contracted Haemophilus influenzae type b, a nasty bacterial illness that can cause mild symptoms in some children, but triggers dangerous, more systemic disease in others — things like meningitis, pneumonia, and sepsis. —Helen Branswell, STAT, 2 Mar. 2026

Hundreds of people infected with measles over the past year — more than 1 in 10, according to the CDC — have been hospitalized with dangerously high fever, pneumonia, trouble breathing and dehydration. —Erika Edwards, NBC news, 1 Mar. 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