sleuthhound

a person not on the police force who investigates criminal or illicit activity or searches for missing persons the fictional sleuthhound Miss Marple is notable for her age as well as for her understanding of human nature, both of them being rather advanced Synonyms dick, gumshoe, hawkshaw, investigator, operative, private detective, private eye, private investigator, shamus [slang], sherlock, sleuth, detectiveRelated Words shadow, tail, tracer, tracker; fed, Federal, G-man, narc (or nark) [slang], plainclothesman