The dog breed that gets its name from a Latin word meaning "earth" because it was used to hunt underground pests is the Terrier. The name "Terrier" is derived from the Latin word "terra," meaning "earth," reflecting the breed's historical purpose of digging into burrows to chase and capture rodents and other small game. Terriers were bred for their tenacity, agility, and ability to work underground, making them valuable for pest control and hunting tasks. The term "Terrier" is now used to describe a group of dog breeds with similar characteristics and hunting instincts.