detective vs police officer

detective and police officer both are nouns.

Word	Noun	Adjective	Verb	Adverb
detective	Yes	No	No	No
police officer	Yes	No	No	No

As nouns, police officer is a hypernym of detective; that is, police officer is a word with a broader meaning than detective:

Other hypernyms of detective include officer.

detective (noun)	police officer (noun)
a police officer who investigates crimes	a member of a police force
an investigator engaged or employed in obtaining information not easily available to the public