incidence vs timing

incidence

noun
  • The act of something happening; occurrence. 

  • The falling of a point on a line, or a line on a plane. 

  • The striking of radiation or a projectile upon a surface. 

  • The manner of falling; bearing or onus, as of a tax that falls unequally. 

  • The extent or the relative frequency of something happening. 

  • A measure of the rate of new occurrence of a given medical condition in a population within a specified period of time. 

timing

noun
  • The time when something happens. 

  • The synchronization of the firing of the spark plugs in an internal combustion engine. 

  • The regulation of the pace of e.g. an athletic race, the speed of an engine, the delivery of a joke, or the occurrence of a series of events. 

  • An instance of recording the time of something. 

How often have the words incidence and timing occurred in a corpus of books? (source: Google Ngram Viewer )