n. A subordinate occurrence or thing; an incident; something incidental or casual.n. The manner of falling; direction of the line of fall; course.n. 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.n. In astronomy, same as immersion, 4.n. In geometry, the situation of two figures in which they have something more in common than they would have in some other situation, but do not completely coincide.n. In gunnery, the angle which the longer axis of a projectile makes with the surface struck.n. The actual fall of taxation upon a particular individual or piece of property, in distinction from its nominal or supposed distribution.