incidence

American  

[in-si-duhns] / ˈɪn sɪ dəns /

noun

• incidences
  plural

1. the rate or range of occurrence or influence of something, especially of something unwanted.

   the high incidence of heart disease in men over 40.

2. a falling upon, affecting, or befalling; occurrence.

   The incidence of murder that Sunday afternoon shocked the sleepy village.

3. Optics, Physics.

   1. the striking of a ray of light, beam of electrons, etc., on a surface, or the direction of striking.

   2. angle of incidence.

4. the fact or the manner of being incident.

5. Geometry. partial coincidence of two figures, as of a line and a plane containing it.

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incidence British  

/ ˈɪnsɪdəns /

noun

1. degree, extent, or frequency of occurrence; amount

   a high incidence of death from pneumonia

2. the act or manner of impinging on or affecting by proximity or influence

3. physics the arrival of a beam of light or particles at a surface See also angle of incidence

4. geometry the partial coincidence of two configurations, such as a point that lies on a circle

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Other Word Forms

Noun Inflected Forms

• incidences
  plural

Etymology

Origin of incidence

First recorded in 1375–1425; late Middle English, from Late Latin incidentia. See incident, -ence

Explanation

Incidence means the frequency with which something bad occurs. You’ll hear of “incidences of cancer” or “incidences of war." You hope the incidence is decreasing, not increasing. You might confuse incidence and incident. They sound similar, but incident refers only to something that happened, not to the frequency with which it happens. After a car accident, the police file an incident report, which is a fancy way of saying they write down what happened. Looking at these reports grouped together can show you if the incidence of accidents at specific intersections in town is on the rise.

Example Sentences

See Examples For:

incidence incidences

"Lip and oral cavity cancer was the seventh leading cancer type in cancer incidence and mortality rate worldwide in adolescents, young adults, and middle-aged adults in 2022," says Daniell.

From Science Daily ● Aug. 4, 2026

"We now see that incidence is also increasing in white populations too, showing that this public health challenge is broadening across the generations," she added.

From BBC ● Jul. 22, 2026

Since 2011, incidence of most food-borne illness has remained flat.

From The Wall Street Journal ● Jul. 22, 2026

In fact, adding more qubits usually corresponds with a higher incidence of errors.

From Barron's ● Jun. 22, 2026

But need the angle of reflection be equal to the angle of incidence in any universe?

From "The Invention of Science" by David Wootton

One example featured a patient hospitalized for gout who told viewers that they "can reduce your incidences of gout if you cut back on your salt, your alcohol, and your red meat."

From Science Daily ● Jan. 9, 2026

But they said it was difficult to fully understand the extent of the problem because there was no national system to collect data on incidences of poor behaviour.

From BBC ● May 7, 2025

But even her backers admit as one put it to me that she is a “work in progress,” more vulnerable to foot in mouth moments as well as incidences of triumph.

From BBC ● Oct. 9, 2024

The bill, which is being considered by the governor, would require the state to publish online data citing any incidences of abuse and uses of isolation in teenage treatment facilities against teenagers.

From Los Angeles Times ● Sep. 26, 2024

While these new incidences of yellow fever were few and scattered, they demonstrated clearly that the disease had not been completely wiped out.

From "An American Plague: The True and Terrifying Story of the Yellow Fever Epidemic of 1793" by Jim Murphy

Related Words

• extent
• frequency
• percentage
• prevalence
• proportion
• rate