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

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

From The Wall Street Journal ● Jul. 22, 2026

But researchers believe it may provide an unexpected advantage - the incidence of diseases such as cancer and diabetes among Laron patients is lower than in the general population.

From BBC ● Jul. 17, 2026

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

From Barron's ● Jun. 22, 2026

Overall, studies of high-dose B vitamin supplements taken over long periods have not shown clear protective effects against cancer incidence or cancer deaths.

From Science Daily ● May 27, 2026

By 1950 the incidence of Dutch elm disease in New York City had been reduced to %o of 1 per cent of the city’s 55,000 elms.

From "Silent Spring" by Rachel Carson

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

"If incidences of this nature do occur, immediate and appropriate action is taken," the club said.

From BBC ● Dec. 24, 2024

The DOC responds to around 85 incidences a year on average, mostly consisting of single animals.

From BBC ● Nov. 25, 2024

In recent months, several major retailers have scaled back on self-checkout machines, citing customer feedback, increased shoplifting incidences and profit losses as key factors in their decisions.

From Salon ● Jul. 17, 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