incidence

noun

in·​ci·​dence ˈin(t)-sə-dən(t)s 

-ˌden(t)s

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

a

: angle of incidence

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

The rise in cancer incidence among younger ages also could have major implications for the future of cancer care, as some types of cancer in younger people may need more aggressive therapies, Iyengar said. —Jacqueline Howard, CNN, 16 Jan. 2025

Then, either slow-release fertilizers or organics gradually provide nutrients to soils, significantly preventing incidences of leaching, where nutrients are drained through the soil profile. —Anthony Reardon, Kansas City Star, 10 Jan. 2025

Pruning overgrown plants opens up the center of the plant, which can reduce the incidence of fungal diseases and make watering a lot easier too. Propagation. —Lauren Landers, Better Homes & Gardens, 8 Jan. 2025

People may also pursue microdosing to reduce the incidence or severity of side effects such as nausea, vomiting or stomach discomfort, according to Stanford. —Shiv Sudhakar, Fox News, 5 Jan. 2025

Word History

First Known Use

1626, in the meaning defined at sense 2a

Phrases Containing incidence

• angle of incidence

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Kids Definition

incidence

noun

in·​ci·​dence ˈin(t)-səd-ən(t)s 

-sə-ˌden(t)s

1

: angle of incidence

2

: rate of occurrence

a high incidence of illness

Medical Definition

incidence

noun

in·​ci·​dence ˈin(t)-səd-ən(t)s, -sə-ˌden(t)s 

1

a

: angle of incidence

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 incidence

—Science

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