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

The Centers for Disease Control and Prevention reported Thursday that there were 2,371 confirmed measles cases nationwide this year, marking the highest incidence of cases since 1991.

From Los Angeles Times ● Aug. 2, 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

Judging by the present incidence of the disease, the American Cancer Society estimates that 45,000,000 Americans now living will eventually develop cancer.

From "Silent Spring" by Rachel Carson

According to available data, around twenty incidences were reported in the maritime area along the French Riviera between the 16th century and the early 2000s with waves often exceeding two meters.

From Science Daily ● May 21, 2026

Many have been on higher alert in recent years as incidences of antisemitism increase across the country.

From BBC ● Mar. 12, 2026

Their incidences, however, grew significantly worse in wartime, especially among civilians who didn’t have the same access to doctors and medical hospitals as armed groups.

From Salon ● Jul. 20, 2025

"Whilst these are historical allegations, incidences brought to our attention where these expectations are not met, are thoroughly investigated and addressed appropriately."

From BBC ● Nov. 28, 2024

Inaccurate data from countries with high incidences of MDR have made it difficult for pharmaceutical companies to meet demand for these drugs consistently, and therefore market prices have fluctuated.

From "Mountains Beyond Mountains" by Tracy Kidder and Michael French

Related Words

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