epidemiology

noun

ep·​i·​de·​mi·​ol·​o·​gy ˌe-pə-ˌdē-mē-ˈä-lə-jē How to pronounce epidemiology (audio)
-ˌde-mē-
1
: a branch of medical science that deals with the incidence, distribution, and control of disease in a population
2
: the sum of the factors controlling the presence or absence of a disease or pathogen

Examples of epidemiology 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.
Malcolm Gladwell, a longtime staff writer at The New Yorker, often uses ideas from the social sciences and epidemiology and applies them to surprising topics. — David Remnick, New Yorker, 18 Sep. 2026 Brandon Marshall is a professor of epidemiology at the Brown University School of Public Health, and director of the People, Place, and Health Collective at Brown. — Abdullah Shihipar, STAT, 1 Sep. 2026 Their epidemiology team continues to closely track the numbers along with other indicators. — Joseph Hernandez august 26, Kansas City Star, 26 Aug. 2026 Tyler VanderWeele is a professor of epidemiology at Harvard University. — Wendy R. Anderson, Washington Post, 24 Aug. 2026 See All Example Sentences for epidemiology

Word History

Etymology

borrowed from French, Spanish, or New Latin; French épidémiologie, borrowed from Spanish epidemiología, borrowed from New Latin epidēmiologia, from Medieval Latin epidēmia "disease affecting a large number of individuals, epidemic" + New Latin -o- -o- + -logia -logy — more at epidemic entry 1

Note: New Latin epidēmiologia was used in the title of a treatise by the Calabrian physician Quinto Tiberio Angelerio (1532-1617), Epidemiologia, sive Tractatus de peste (Madrid, 1598), a second edition of his earlier work Ectypa pestilentis status Algheriae Sardiniae (Cagliari, 1588), detailing methods to cope with a plague outbreak in Alghero, Sardinia, in 1582-83. The Latin word was revived by the Spanish physician Joaquín de Villalba (1752-1807) in his Epidemiología española (Madrid, 1802), a history of epidemics in Spain that was widely disseminated in Europe.

First Known Use

1850, in the meaning defined at sense 1

Time Traveler
The first known use of epidemiology was in 1850

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Cite this Entry

“Epidemiology.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/epidemiology. Accessed 25 Sep. 2026.

Kids Definition

epidemiology

noun
1
: a branch of medical science that deals with the occurrence, distribution, and control of disease in a population
2
: the sum of the factors controlling the presence or absence of a particular disease

Medical Definition

epidemiology

noun
ep·​i·​de·​mi·​ol·​o·​gy -jē How to pronounce epidemiology (audio)
plural epidemiologies
1
: a branch of medical science that deals with the incidence, distribution, and control of disease in a population
2
: the sum of the factors controlling the presence or absence of a disease or pathogen

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