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

In addition to the requirements in law, the Florida Department of Health has vaccination requirements for hepatitis B; varicella, commonly known as chickenpox; Haemophilus influenza type b, or Hib, which can cause meningitis; and pneumococcal conjugate, which can cause pneumonia and meningitis. —Jim Saunders, Sun Sentinel, 27 Jan. 2026

At the time, his medical team believed Quinton could be experiencing Type A flu and pneumonia. —Rachel Raposas, PEOPLE, 27 Jan. 2026

There are serious complications of pneumonia (1 in 20), encephalitis (brain swelling) in 1/1,000, deafness in many and deaths in 1-3/1,000. —Judy Stone, Forbes.com, 24 Jan. 2026

When temperatures drop below freezing, wet and cold conditions may lead to medical issues such as pneumonia or hypothermia. —Sergio Candido, CBS News, 24 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