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
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Health leaders like Allegheny County Health Department infectious disease epidemiology program manager Jen Fiddner said misinformation has driven people away from getting the vaccine to prevent outbreaks. — Chris Hoffman, CBS News, 28 Sep. 2026 Those first days after the initial anthrax case, our muscle memory focused us on the important work of traditional shoe-leather epidemiology. — Daniel Jernigan, STAT, 26 Sep. 2026 The statement, led by Jordana Cohen, associate professor of medicine and epidemiology at the Perelman School of Medicine at the University of Pennsylvania, concludes that cuffless models are not yet ready to diagnose or manage hypertension. — Hanna Wickes, Fort Worth Star-Telegram, 24 Sep. 2026 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 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 1 Oct. 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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