Something done or to be done; business. Transactions and other matters of professional or public business: affairs of state. An occurrence, event, or matter: The senator's death was a tragic affair. A social function. An object or a contrivance: Their first car was a ramshackle affair. A matter of personal concern. Personal business: get one's affairs in order. A matter causing public scandal and controversy: the Dreyfus affair. A romantic and sexual relationship, sometimes one of brief duration, between two people who are not married to each other.