incidence

1. The act of something happening; occurrence. (countable, uncountable)
2. The extent or the relative frequency of something happening. (countable, uncountable)
3. The manner of falling; bearing or onus, as of a tax that falls unequally. (countable, uncountable)
4. The striking of radiation or a projectile upon a surface. (countable, uncountable)
5. A measure of the rate of new occurrence of a given medical condition in a population within a specified period of time. (countable, uncountable)
6. The falling of a point on a line, or a line on a plane. (countable, uncountable)
7. The relation between an edge of a graph and one of the vertices it connects. (countable, uncountable)

Plural incidences