contagious disease

noun

plural contagious diseases
: 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.
Measles is one of the most contagious diseases known to humans. Mary Kekatos, ABC News, 28 Feb. 2025 Texas child dies in first US measles death since 2015 Texas authorities on Wednesday announced the first measles death in the state's outbreak of the highly contagious disease. Jane Onyanga-Omara, USA TODAY, 27 Feb. 2025 Though measles was largely eradicated from the U.S. around the turn of the century thanks to a vaccine that is 97% effective, the rise of vaccine skepticism in recent years has led to a bit of a comeback for the highly contagious disease. Joseph Wilkinson, New York Daily News, 27 Feb. 2025 So have programs for monitoring and deploying rapid-response teams for contagious diseases such as an Ebola outbreak in Uganda. Ellen Knickmeyer, Chicago Tribune, 5 Feb. 2025 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 4 Mar. 2025.

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.

More from Merriam-Webster on contagious disease

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!