Bloodhound's Clue is a term used to describe the ability of a bloodhound to track a SCENT. This ability is based on the dog's powerful sense of SMELL, which is why the crossword solutions for this term are 'SMELL', 'SCENT' and 'ODOR'. All three words refer to the same thing, which is the ability of an animal or person to detect and identify odors. Bloodhounds are renowned for their ability to follow a SCENT, making them invaluable in search and rescue operations.