a breed of large powerful hound of European origin having very acute smell and used in tracking
"The tracker released the bloodhound, whose incredible sense of smell quickly led them to the missing person's trail."
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.
"The police deployed a bloodhound to track the fugitive across three states after his scent was still detectable from two weeks ago."
In plain English: A bloodhound is a large dog with an amazing sense of smell that can track people over long distances.
"The police sent out a bloodhound to track down the missing boy's scent in the woods."
Usage: Do not confuse this breed with the unrelated "bloodhound" surname or any other canine variety; it specifically refers to the large scenthound known for tracking cold cases. In casual conversation, avoid using it as a metaphor for an overly suspicious person unless emphasizing extreme persistence in following a trail.
The word bloodhound comes directly from Middle English, combining "blood" and "hound." Its name refers to the animal's remarkable ability to track scents by following a person's trail.