crossing guard vs traffic cop

crossing guard and traffic cop both are nouns.

Word	Noun	Adjective	Verb	Adverb
crossing guard	Yes	No	No	No
traffic cop	Yes	No	No	No

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

crossing guard: someone who helps people (especially children) at a traffic crossing
traffic cop: a policeman who controls the flow of automobile traffic

crossing guard (noun)	traffic cop (noun)
someone who helps people (especially children) at a traffic crossing	a policeman who controls the flow of automobile traffic