contagious disease

noun

plural contagious diseases
Synonyms of contagious diseasenext
: an infectious disease (such as influenza, measles, or tuberculosis) that is transmitted by contact with an infected individual or infected bodily discharges or fluids (such as respiratory droplets), by contact with a contaminated surface or object, or by ingestion of contaminated food or water

Note: The terms contagious disease and communicable disease are often used interchangeably. However, communicable diseases such as malaria or schistosomiasis that are spread by contact with disease vectors (such as mosquitoes or ticks) are not typically considered to be "contagious" diseases since they cannot be spread from direct contact with another person.

Examples of contagious disease in a Sentence

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.
Screwworm is not a contagious disease that spreads from animal to animal. Jen Christensen, CNN Money, 4 June 2026 Those threats include measles — one of the world’s most contagious diseases — as well as respiratory viruses such as Covid-19 and influenza. Annika Kim Constantino, CNBC, 4 June 2026 Eighteen Americans possibly exposed to the virus are undergoing a six-week-long quarantine — much lengthier than the guidelines for most contagious diseases. Ashley Abramson, Washington Post, 23 May 2026 How does contagious disease spread? Allison Gibson, Sacbee.com, 7 May 2026 See All Example Sentences for contagious disease

Word History

First Known Use

1529, in the meaning defined above

Time Traveler
The first known use of contagious disease was in 1529

Cite this Entry

“Contagious disease.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/contagious%20disease. Accessed 10 Jun. 2026.

Medical Definition

contagious disease

noun
: an infectious disease (as influenza, measles, or tuberculosis) that is transmitted by contact with an infected individual or infected bodily discharges or fluids (as respiratory droplets), by contact with a contaminated surface or object, or by ingestion of contaminated food or water

Note: The terms contagious disease and communicable disease are often used interchangeably. However, communicable diseases (as malaria or schistosomiasis) that are spread by contact with disease vectors (as mosquitoes or ticks) are not typically considered to be "contagious" diseases since they cannot be spread from direct contact with another person.

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