A terrier's a dog of any one of many breeds or landraces of terrier type, which are typically small, wiry, very active and fearless dogs. History Most terrier breeds were developed in Great Britain and Ireland. They were used to control rats, rabbits, and foxes both over and under the ground. Some larger terriers were also used to hunt badgers. In fact, the word terrier comes from the Middle French terrier, derived from the Latin terra, meaning earth. The Kerry Blue Terrier and Airedale, howe… (More on Terrier)