lollipop lady vs crossing guard

lollipop lady and crossing guard both are nouns.

Word	Noun	Adjective	Verb	Adverb
lollipop lady	Yes	No	No	No
crossing guard	Yes	No	No	No

As nouns, crossing guard is a hypernym of lollipop lady; that is, crossing guard is a word with a broader meaning than lollipop lady:

lollipop lady: a woman hired to help children cross a road safely near a school
crossing guard: someone who helps people (especially children) at a traffic crossing

Other hypernyms of lollipop lady include adult female, woman.

lollipop lady (noun)	crossing guard (noun)
a woman hired to help children cross a road safely near a school	someone who helps people (especially children) at a traffic crossing