incidence

noun

Synonyms of incidencenext
1
a
: rate of occurrence or influence
a high incidence of crime
b
: an act or the fact or manner of falling upon or affecting : occurrence
2
b
: the arrival of something (such as a projectile or a ray of light) at a surface

Did you know?

The words incident, incidence, and instance may seem similar (and, in fact, incident and incidence are closely related), but they are applied in different ways. In current use, incidence usually means "rate of occurrence" and is often qualified in some way ("a high incidence of bear sightings"). Incident usually refers to a particular event, often something unusual or unpleasant ("many such incidents go unreported"). Instance suggests a particular occurrence that is offered as an example ("another instance of a simple change bringing real improvement"); it can also be synonymous with case ("many instances/cases in which the wrong form was submitted"). The plural incidences sometimes occurs in such contexts as "several recent incidences of bear sightings," but this use is often criticized as incorrect.

Examples of incidence in a Sentence

an increased incidence of diabetes a high incidence of criminal behavior
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.
Studies show that the disease occurs in up to three per cent of pregnancies, though the real incidence may be higher, according to the Hyperemesis Education and Research Foundation (HER). The New Yorker, New Yorker, 7 Aug. 2026 Such hotspot maps could become a useful source of information for the public to help determine their risk for Lyme disease, and also provide deeper insight into where ticks move and how that affects the incidence of Lyme. Alice Park, Time, 7 Aug. 2026 One analysis of Medicare beneficiaries aged 65 and older found nearly 60,000 incident cases of NTM pulmonary disease from 2010 to 2019, with incidence highest in the South and among women, Asian individuals and people aged 80 and older. Matt Emma, USA Today, 7 Aug. 2026 Black men have a prostate cancer incidence rate nearly 70% higher than that of white men and are two to four times more likely to die from the disease than men in other racial and ethnic groups, according to the American Cancer Society. Hanna Wickes, Charlotte Observer, 7 Aug. 2026 See All Example Sentences for incidence

Word History

First Known Use

1626, in the meaning defined at sense 2a

Time Traveler
The first known use of incidence was in 1626

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Cite this Entry

“Incidence.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/incidence. Accessed 9 Aug. 2026.

Kids Definition

incidence

noun
1
2
: rate of occurrence
a high incidence of illness

Medical Definition

1
b
: the arrival of something (as a ray of light) at a surface
2
a
: an act or the fact or manner of occurring or affecting
diseases of domestic incidenceScience
b
: rate of occurrence or influence
especially : the rate of occurrence of new cases of a particular disease in a population being studied compare prevalence

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