1 (often foll. by of) the fact, manner, or rate, of occurrence or action.
2 the range, scope, or extent of influence of a thing.
3 Physics the falling of a line, or of a thing moving in a line, upon a surface.
4 the act or an instance of coming into contact with a thing.
Phrases and idioms:
angle of incidence the angle which an incident line, ray, etc., makes with the perpendicular to the surface at the point of incidence.
Etymology: ME f. OF incidence or med.L incidentia (as INCIDENT)
Useful english dictionary. 2012.