An Event

1. An occurrence; something that happens.
2. A prearranged social activity (function, etc.)
3. One of several contests that combine to make up a competition.
4. An end result; an outcome (now chiefly in phrases).
5. (physics) A point in spacetime having three spatial coordinates and one temporal coordinate.
6. (computing) A possible action that the user can perform that is monitored by an application or the operating system (event listener). When an event occurs an event handler is called which performs a specific task.
7. (probability theory) A set of some of the possible outcomes; a subset of the sample space. Event (probability theory) - Wikipedia
8. (obsolete) An affair in hand; business; enterprise.
9. (medicine) An episode of severe health conditions.