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.
The schedule was designed around decades of immunology and epidemiology research, with extensive evidence review by vaccine experts. Omer Awan, Forbes.com, 2 Aug. 2026 The study design is a natural experiment, says Victor Henderson, MD, a professor of epidemiology and neurology at Stanford Neuroscience Health Center in California who wasn’t involved in the new research. Emily Kay Votruba, EverydayHealth.com, 29 July 2026 Paul released a treasure trove of private diary entries and emails from Fauci to celebrity pals, friends, allied media figures, or his peers in epidemiology. Ian Miller Outkick, FOXNews.com, 28 July 2026 Lead author Michael LaMonte, research professor of epidemiology and environmental health at the University at Buffalo, said the entry point can be simple. Samantha Agate, Sacbee.com, 23 July 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 5 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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