ruralist vs adult male

ruralist and adult male both are nouns.

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

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

Other hypernyms of ruralist include man, rustic.

ruralist (noun)	adult male (noun)
an advocate of rural living	an adult person who is male (as opposed to a woman)
a man who lives in the country and has country ways