A bloodhound is a large dog with a very good sense of smell. Bloodhounds are often used to find people or other animals by following their scent.
bloodhound in British English
(ˈblʌdˌhaʊnd)
noun
1.
a large breed of hound having a smooth glossy coat of red, tan, or black and loose wrinkled skin on its head: formerly much used in tracking and police work
2. informal
a detective
bloodhound in American English
(ˈblʌdˌhaʊnd)
noun
1.
any of a breed of large dogs with a smooth coat, wrinkled face, drooping ears, and a keen sense of smell
bloodhounds are used in tracking escaped prisoners, fugitives, etc.