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.
For these patients, and their loves ones, the epidemiology is forever meaningless. David N. Hackney, STAT, 26 Aug. 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 That was one of my biggest takeaways — and bummers — from my conversation with Chris Barker, an epidemiology professor at UC Davis who has studied mosquitoes for almost 30 years, including at his lab. Jaclyn Cosgrove, Los Angeles Times, 13 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 31 Aug. 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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