The term "giant breed" refers to a group of dog breeds that are known for their large size. These dogs typically have an adult height of over 24 inches and can weigh anywhere from 100-200 pounds or more, depending on the specific breed. Some popular giant breeds include the Great Dane, Irish Wolfhound, Newfoundland, St. Bernard, and Scottish Deerhound, among others. These dogs were originally bred for various purposes such as hunting, herding, and companionship, but their large size makes them more suitable for families with plenty of space or those who lead active lifestyles.