occasion

(ə-kāˈzhən)

1. a. An event or happening; an incident.
   b. The time at which an event occurs.
2. A significant event.
3. A favorable or appropriate time or juncture; an opportunity. See Synonyms at opportunity.
4. Something that brings on or precipitates an action, condition, or event, especially the immediate cause. See Synonyms at cause.
5. Something that provides a reason or justification; a ground.
6. A need created by a particular circumstance: “He must buy what he has little occasion for” (Laurence Sterne).
7. A large or important social gathering.
8. occasions Archaic Personal requirements or necessities.