incidence

noun7

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