Definition of Coincidence

Noun: coincidence  kow'in-si-d(u)n(t)s

1. An event that might have been arranged although it was really accidental
   - happenstance
    
2. The quality of occupying the same position or area in space
   "he waited for the coincidence of the target and the cross hairs"
    
3. The temporal property of two things happening at the same time
   "the interval determining the coincidence gate is adjustable";
   - concurrence, conjunction, co-occurrence

See also:
coincided
coincidences