The term TERHUNE DOG is a reference to the breed of dog known as the Airedale Terrier, which was developed by American author and animal breeder Albert Payson Terhune in the early 1900s. The crossword solution LAD is an acronym for the breed's full name, which stands for 'Lakeland Airedale Terrier.' This breed is known for its intelligence, loyalty, and strength, and is often used as a guard dog or hunting companion.