brony vs adult male

brony and adult male both are nouns.

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

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

Other hypernyms of brony include buff, devotee, fan, lover, man.

brony (noun)	adult male (noun)
an adult, male fan of the show My Little Pony: Friendship is Magic	an adult person who is male (as opposed to a woman)