lollipop man vs adult male

lollipop man and adult male both are nouns.

Word	Noun	Adjective	Verb	Adverb
lollipop man	Yes	No	No	No
adult male	Yes	No	No	No

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

lollipop man: a man hired to help children cross a road safely near a school
adult male: an adult person who is male (as opposed to a woman)

Other hypernyms of lollipop man include crossing guard, man.

lollipop man (noun)	adult male (noun)
a man hired to help children cross a road safely near a school	an adult person who is male (as opposed to a woman)