dick vs investigator

dick and investigator both are nouns.

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

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

Other hypernyms of dick include detective, police detective, tec.

dick (noun)	investigator (noun)
obscene terms for penis	someone who investigates
someone who is a detective	a scientist who devotes himself to doing research
	a police officer who investigates crimes