This term is overworked as an approximate synonym for commerce, traffic, trade, industry, calling, vocation, company, firm, duty, or employment. Expressions such as "to mean business," "get down to business," "mind one's own business," and "have no business" are as trite as they are inexact."To give one the business (or the works)" is slang at its best — or worst.
Dictionary of problem words and expressions. Harry Shaw. 1975.