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
epidemiological adjective
or less commonly epidemiologic
epidemiologically adverb

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 latest case was reported by France and involved a passenger who disembarked the ship one day earlier, Olivier le Polain, unit head of epidemiology and analytics for response with the WHO, said. Janet Loehrke, USA Today, 12 May 2026 Juan Petrina, director of epidemiology for the Tierra del Fuego province, shows a laptop screen after a news conference in Ushuaia on Friday. Marlene Lenthang, NBC news, 10 May 2026 Among the attendees that gathered that morning in the Palais des Nations for the discussions was Svetlana Pozhidaeva, who, by her own admission, had no expertise in epidemiology or foreign aid. Jessica Mathews, Fortune, 9 May 2026 The epidemiology tells a different story. Katrine L. Wallace, The Conversation, 28 Apr. 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

Browse Nearby Words

Cite this Entry

“Epidemiology.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/epidemiology. Accessed 12 May. 2026.

Kids Definition

epidemiology

noun
ep·​i·​de·​mi·​ol·​o·​gy ˌep-ə-ˌdē-mē-ˈäl-ə-jē How to pronounce epidemiology (audio)
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
epidemiological adjective
also epidemiologic

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
epidemiological adjective
also epidemiologic
epidemiologically adverb

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