bachelor vs adult male

bachelor and adult male both are nouns.

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

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

Other hypernyms of bachelor include man.

bachelor (noun)	adult male (noun)
a man who has never been married	an adult person who is male (as opposed to a woman)
a knight of the lowest order; could display only a pennon

bachelor (verb)	adult male (verb)
lead a bachelor's existence