businessman vs man of affairs

businessman and man of affairs both are nouns.

Word	Noun	Adjective	Verb	Adverb
businessman	Yes	No	No	No
man of affairs	Yes	No	No	No

As nouns, businessman and man of affairs are synonyms defined as:

businessman and man of affairs: a person engaged in commercial or industrial business (especially an owner or executive)

businessman (noun)	man of affairs (noun)
a person engaged in commercial or industrial business (especially an owner or executive)	a person engaged in commercial or industrial business (especially an owner or executive)