incidence
noun
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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
Max Goldbart, Deadline, 14 May 2026
Malaria incidence has increased, measles coverage remains below the threshold needed to prevent outbreaks, and maternal and child mortality decline is slowing, the report found.
—Claire Cameron, Scientific American, 13 May 2026
The study noted a potential, but rare, elevation in anaphylaxis incidence rates following 2023-2024 Pfizer-BioNTech COVID-19 vaccination — affecting about 1 in 1 million people.
—Nathaniel Weixel, The Hill, 6 May 2026
While incidence rises with age, around 4% of people with Parkinson’s are diagnosed before age 50.
—Samantha Agate, Fort Worth Star-Telegram, 6 May 2026
See All Example Sentences for incidence
Cite this Entry
“Incidence.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/incidence. Accessed 21 May. 2026.
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