| one of any of several breeds of usually large, powerful dogs originally developed to assist people in their daily work, as draft animals, guard dogs, and guide dogs, and including the boxer, bullmastiff, Doberman pinscher, Great Dane, St. Bernard, and Siberian Husky. |
| working dog n. Any of various breeds of dogs developed or trained to do useful work, such as herding animals, pulling wagons or sleds, or guarding property. |