BLOODHOUND
bloodhound, sleuthhound
(noun) a breed of large powerful hound of European origin having very acute smell and used in tracking
Source: WordNet® 3.1
Etymology
Noun
bloodhound (plural bloodhounds)
A large scenthound famed for its ability to follow a scent many days old, over vast distances. This dog is often used as a police dog to track missing people, fleeing suspects, or escaped prisoners.
(figurative) A detective or other person skilled at finding people or clues.
(archaic) A bloodthirsty person.
Source: Wiktionary
Blood"hound` (, n.
Definition: A breed of large and powerful dogs, with long, smooth, and
pendulous ears, and remarkable for acuteness of smell. It is employed
to recover game or prey which has escaped wounded from a hunter, and
for tracking criminals. Formerly it was used for pursuing runaway
slaves. Other varieties of dog are often used for the same purpose
and go by the same name. The Cuban bloodhound is said to be a variety
of the mastiff.
Source: Webster’s Unabridged Dictionary 1913 Edition