1. Business of any kind; that which is done, or is to be done; a word of very indefinite and undefinable signification. In the plural, it denotes transactions in general; as human affairs; political or ecclesiastical affairs: also the business or concerns of an individual; as, his affairs are embarrassed.
2. Matters; state; condition of business or concerns.
I have sent that ye may know our affairs. Eph 6.
3. In the singular, it is used for a private dispute, or duel; as, an affair of honor; and sometimes a partial engagement of troops.
In the phrase, at the head of affairs, the word means, the public concerns of executing the laws and administering the government.