Simple Definition of incidence
: the number of times something happens or develops : the rate at which something occurs
: the angle at which a ray (such as a ray of light) hits a surface
Examples of incidence in a sentence
an increased incidence of diabetes
a high incidence of criminal behavior
Did You Know?
The words incident, incidence, and instance may seem similar (and, in fact, incident and incidence are closely related), but they are not used identically. In current use, incidence usually means "rate of occurrence" and is often qualified in some way ("a high incidence of diabetes"). 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 bureaucratic bumbling"); it can also be synonymous with case ("many instances in which the wrong form was submitted"). The plural incidences sometimes occurs in such contexts as "several recent incidences of crime," but this use is often criticized as incorrect.
First Known Use of incidence
Medical Definition of incidence
1a: angle of incidenceb: the arrival of something (as a ray of light) at a surface
2a: 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
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