anything done or to be done; anything requiring action or effort; business; concern: an affair of great importance.
2.
affairs, matters of commercial or public interest or concern; the transactions of public or private business or finance: affairs of state; Before taking such a long trip you should put all your affairs in order.
3.
an event or a performance; a particular action, operation, or proceeding: When did this affair happen?
4.
thing; matter (applied to anything made or existing, usually with a descriptive or qualifying term): Our new computer is an amazing affair.
5.
a private or personal concern; a special function, business, or duty: That's none of your affair.
Origin: 1250–1300; earlier affaire < French, Old French afaire for a faire to do, equivalent to a (< Latin ad to) + faire ≪ Latin facere; replacing Middle English afere < Old French
c.1300, "what one has to do," from Anglo-Norm. afere, from O.Fr. afaire, from the infinitive phrase à faire "to do" (from L. ad "to" + facere "to do, make;" see factitious). A Northern word originally, brought into general use and given a Fr. spelling by Caxton