tracer vs police detective

tracer and police detective both are nouns.

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

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

tracer: an investigator who is employed to find missing persons or missing goods
police detective: a police officer who investigates crimes

Other hypernyms of tracer include detective, investigator, tec.

tracer (noun)	police detective (noun)
ammunition whose flight can be observed by a trail of smoke	a police officer who investigates crimes
(radiology) any radioactive isotope introduced into the body to study metabolism or other biological processes
an instrument used to make tracings
an investigator who is employed to find missing persons or missing goods