man of affairs vs businessman

man of affairs and businessman both are nouns.

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

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

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

man of affairs (noun)	businessman (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)