A limer, or lymer, was a kind of dog, a scenthound, used on a leash in medieval times to find large game before it was hunted down by the pack. It was sometimes known as a lyam hound/dog or lime-hound, from the Middle English word lyam, meaning 'leash'. The French cognate limier has sometimes been used for the dogs in English as well. The type is not to be confused with the bandog, which was also a dog controlled by a leash, typically a chain, but was a watchdog or guard dog.

Scent hounds are a type of hound that primarily hunts by scent rather than sight. These breeds are hunting dogs and are generally regarded as having some of the most sensitive noses among dogs. Scent hounds specialize in following scent or smells. Most of them tend to have long, drooping ears and large nasal cavities to enhance smell sensitivity. They need to have relatively high endurance to be able to keep track of scent over long distances and rough terrain. It is believed that they were first bred by the Celts by crossbreeding mastiff-type dogs with sighthounds. The first established scent hounds were St. Hubert Hounds bred by monks in Belgium during the Middle Ages.