noun A prearranged social activity (function, etc.)
I went to an event in San Francisco last week.
noun One of several contests that combine to make up a competition.
noun An end result; an outcome (now chiefly in phrases).
In the event, he turned out to have what I needed anyway.
noun A remarkable person.
noun A point in spacetime having three spatial coordinates and one temporal coordinate.
noun 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.
noun A set of some of the possible outcomes; a subset of the sample space.
If X is a random variable representing the toss of a six-sided die, then its sample space could be denoted as {1,2,3,4,5,6}. Examples of events could be: X=1, X=2, X≥5,X≠4, and X∈{1,3,5}.