incidence

The rate or extent of occurrence or effect.

The fact or an instance of happening; occurrence.

The arrival of radiation or a projectile at a surface.

Angle of incidence.

The actual fall of taxation upon a particular individual or piece of property, in distinction from its nominal or supposed distribution.

A subordinate occurrence or thing; an incident; something incidental or casual.

The manner of falling; direction of the line of fall; course.

In physics, the falling or impinging of a ray of light or heat, etc., upon a surface: used especially with reference to the direction of the ray.

In astronomy, same as immersion, 4.