incidence
incidence Lexical Profile
incidence Game Scores & Validity
• noun
The rate, frequency, or extent of the occurrence of something, especially of an undesirable condition such as a disease, crime, or defect.
"Public health officials reported a sharp decline in the incidence of seasonal flu following the vaccination campaign."
In physics and geometry, the intersection of a line, or something moving in a straight line such as a beam of light or sound wave, with a surface.
"In optics, the angle of reflection from a smooth mirror is always equal to the angle of incidence."
In economics, the ultimate distribution of the burden of a tax or cost among different individuals or groups.
"Economists analyzed the incidence of the new corporate tariff to see whether consumers or shareholders bore the cost."
Word Nuance & Usage
Do not confuse 'incidence' (the rate or frequency at which something occurs, usually singular) with 'incidents' (the plural of 'incident', meaning distinct individual events or occurrences). In epidemiology, 'incidence' specifically refers to the rate of new cases over a period, whereas 'prevalence' refers to the total number of existing cases at a given time.
• Nearby Words
Word Origin & Etymology
Borrowed in the late 14th century from Old French 'incidence', from Medieval Latin 'incidentia', derived from the Latin verb 'incidere' meaning 'to fall upon' or 'to happen' (from 'in-' meaning 'upon' and 'cadere' meaning 'to fall').