Pit bull is an umbrella term for several types of dog believed to have descended from bull and terriers. In the United states, the term is usually considered to include the American Pit Bull Terrier, American Staffordshire Terrier, American Bully, Staffordshire Bull Terrier, and sometimes the American Bulldog, along with any crossbred dog that shares certain physical characteristics with these breeds. In other countries, including the United Kingdom.