► event something that happens, especially something important, interesting, or unusual: The Civil War was one of the most important events in U.S. history. Investigators are trying to determine the sequence of events that led to the plane crash (=the order in which events happened).
► occurrence formal something that happens. Used especially when saying how often something happens: Divorce is a common occurrence these days.
► incident something that happens, especially something unusual, serious, or violent: Police were called to the scene after the incident occurred.
► occasion an important social event or celebration: We’re saving the champagne for a special occasion.
► affair something that happens in politics or public life, especially something shocking or illegal: President Nixon was forced to resign after the Watergate affair.
► happening something that happens, especially a strange event: The novel is full of suspense and mysterious happenings.
► phenomenon something that happens in society or nature, especially something that is unusual or difficult to understand: Scientists cannot explain the strange phenomenon of so many birds dying at the same time.