# incidence

Pronunciation: US say "IN-si-duhns" /ˈɪn.sɪ.dəns/; UK

## Noun

1. The extent to which something happens, or how often it occurs across a group or period.
   - Simple: How often something happens, or how common it is.
   - _Researchers noted a rising incidence of burnout among remote workers._
   - _The survey measured the incidence of fraud across small businesses._
2. The fact of something occurring; the actual happening of an event or action.
   - Simple: The fact of something happening or taking place.
   - _Historians debated the incidence of the rebellion and its underlying causes._
   - _The incidence of so many coincidences in one day seemed almost impossible._
3. A measure of the rate at which new cases of a medical condition appear in a population over a specified period.
   - Simple: How many people in a group get a disease over a set period of time.
   - _The study reported a higher incidence of diabetes in urban areas._
   - _Public health officials tracked the incidence of the virus throughout the year._
4. The arrival or striking of radiation, light, or a projectile against a surface.
   - Simple: The hitting of light, rays, or a moving object against a surface.
   - _The angle of incidence equals the angle of reflection for a flat mirror._
   - _Increasing the incidence of laser light improved the sensor's response._
5. The way a burden falls, especially how the real cost of a tax is borne by particular groups.
   - Simple: The way a cost or tax really falls on different people.
   - _Economists analyzed the incidence of the sales tax on low-income households._
   - _The true incidence of the levy shifted from producers to consumers._
6. The lying of a point on a line, or of a line within a plane.
   - Simple: When a point sits on a line, or a line sits on a flat surface.
   - _The proof relied on the incidence of three points along a single line._
   - _Projective geometry studies the incidence of lines and points without any reference to distance._
7. The relation connecting an edge of a graph to one of the vertices it joins.
   - Simple: In a graph, the link between an edge and a point it joins.
   - _The matrix records the incidence of every edge with each vertex._
   - _Each edge contributes to the incidence of exactly two vertices in a simple graph._

## Origin

From Middle French incidence, from Medieval Latin incidentia ("a falling upon"), from Latin incidens, the present participle of incidere ("to fall upon"), formed from in ("on") plus cadere ("to fall").

Source: DictionaryAI, https://dictionaryai.com/define/incidence (written from Wiktionary data, CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/).