A hound is a type of dog bred specifically for hunting. Unlike other dogs that might herd sheep or guard houses, hounds were developed over centuries to help humans track and chase game animals. Different hounds have different specialties: bloodhounds use their incredible sense of smell to follow trails that are days old, while greyhounds rely on their blazing speed to chase down rabbits and other fast prey.

Hounds often have distinctive features that help them hunt. Basset hounds have long, droopy ears that sweep scents up from the ground toward their noses. Beagles work in packs and bay loudly when they catch a scent so hunters can follow them through thick woods. When you hear someone say a dog is “baying,” that's the deep, howling bark many hounds make.

The word also means to pursue someone relentlessly or annoyingly. If reporters hound a celebrity, they follow her everywhere asking questions. A younger brother might hound his sister to play with him, asking again and again. When you hound someone, you're being as persistent as a hunting dog that won't give up the chase.

Some famous hounds in stories include the Hound of the Baskervilles from Sherlock Holmes and the pack of hounds in Where the Red Fern Grows.