eunuch vs adult male

eunuch and adult male both are nouns.

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

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

Other hypernyms of eunuch include man.

eunuch (noun)	adult male (noun)
a man who has been castrated and is incapable of reproduction	an adult person who is male (as opposed to a woman)