Sleuth

n.

1.

The track of man or beast as followed by the scent.

Noun	1.	sleuth - a detective who follows a trail Synonyms: sleuthhound
Verb	1.	sleuth - watch, observe, or inquire secretly Synonyms: snoop, spy, stag

Bow Street runner, FBI, FBI agent, Federal, G-man, Secret Service, Sherlock, Sherlock Holmes, T-man, detective, dick, eye, fed, gumshoe, hawkshaw, hotel detective, house detective, house dick, inquiry agent, investigator, narc, operative, plainclothesman, police detective, private detective, private eye, private investigator, revenuer, shamus, snoop, store detective, tec, treasury agent