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

While northern Mexico has a high incidence of RMSF due to many free-roaming dogs with brown dog ticks, Tecate has not previously been known to be a high-risk RMSF region. —Thomas G. Moukawsher, Newsweek, 29 Nov. 2024

Also, as a positive ‘side benefit,’ semaglutide was also noted to reduce the incidence of diabetes in the group who’d had CABG surgery. —New Atlas, 24 Nov. 2024

The American Cancer Society’s report shared that while breast cancer incidence rates among Black and white women are similar, mortality rates are markedly different, with Black women having a 38 percent higher death rate from breast cancer. —Dominique Fluker, Essence, 21 Oct. 2024

That means Asian women are now tied with white women for the highest breast cancer incidence rates, at 86 cases per 100,000. —Lisa Rapaport, EverydayHealth.com, 7 Oct. 2024

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