coroner vs investigator

coroner and investigator both are nouns.

Word	Noun	Adjective	Verb	Adverb
coroner	Yes	No	No	No
investigator	Yes	No	No	No

As nouns, investigator is a hypernym of coroner; that is, investigator is a word with a broader meaning than coroner:

coroner: a public official who investigates by inquest any death not due to natural causes
investigator: someone who investigates

coroner (noun)	investigator (noun)
a public official who investigates by inquest any death not due to natural causes	someone who investigates
	a scientist who devotes himself to doing research
	a police officer who investigates crimes