Pneumonia (noun)

1. A lung infection caused by bacteria, viruses, or other microorganisms, characterized by inflammation and filling of the alveoli with fluid.
2. A serious lung disease characterized by inflammation and fluid in the lungs.

Origin:

Late 18th century: from greek pneuma "breath, lungs" + -onia (denoting a condition).

Examples:

1. He was diagnosed with pneumonia and had to be hospitalized.
2. She had a severe case of pneumonia and was in the ICU for a week.
3. The elderly are particularly susceptible to pneumonia.
4. The doctor prescribed antibiotics to treat the pneumonia.
5. He contracted pneumonia while traveling in a developing country.