Learner's definition of OCCURRENCE
something that happens
Getting headaches has become a common/frequent/everyday occurrence for her.
a rare/unusual occurrence
the recent occurrences of the disease
Lightning is a natural occurrence.
the fact of happening or occurring
— usually + of
We were trying to prevent the occurrence of further problems. [=trying to prevent further problems from occurring]
The occurrence of theft in the locker room has stopped.
The occurrence of the disease is low. [=the disease does not occur commonly]