1. a situation or matter that is being dealt with or considered
2. an event or activity of a particular type
3. a romantic or sexual relationship between two people, especially when one or both are married to someone else

Examples

• The whole affair was handled very poorly by management.
• The wedding was a grand affair with over 200 guests.
• She discovered her husband was having an affair with his secretary.
• This is a private affair and none of your business.
• The charity gala was an elegant affair held at the hotel.
• Foreign affairs are handled by the State Department.
• The scandal became a public affair when the newspapers got involved.