businessman vs adult male

businessman and adult male both are nouns.

Word	Noun	Adjective	Verb	Adverb
businessman	Yes	No	No	No
adult male	Yes	No	No	No

As nouns, adult male is a hypernym of businessman; that is, adult male is a word with a broader meaning than businessman:

businessman: a person engaged in commercial or industrial business (especially an owner or executive)
adult male: an adult person who is male (as opposed to a woman)

Other hypernyms of businessman include bourgeois, businessperson, man.

businessman (noun)	adult male (noun)
a person engaged in commercial or industrial business (especially an owner or executive)	an adult person who is male (as opposed to a woman)