adult male vs male person

adult male and male person both are nouns.

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

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

Other hypernyms of adult male include adult, grownup, male.

adult male (noun)	male person (noun)
an adult person who is male (as opposed to a woman)	a person who belongs to the sex that cannot have babies