■ noun
1》 the occurrence, rate, or frequency of a disease, crime, or other undesirable thing.
2》 Physics the intersection of a line, or something moving in a straight line, such as a beam of light, with a surface.
3》 the way in which the burden of a tax falls upon the population.
Origin
ME: from OFr., or from med. L. incidentia , from L. incidere (see incident ).