a member of the genus Canis (probably descended from the common wolf) that has been domesticated by man since prehistoric times; occurs in many breeds

a dog trained to guard property

any of various usually long-haired breeds of dog reared to herd and guard sheep

any dog trained to assist police especially in tracking

any of four Swiss breeds

a breed of stocky medium-sized short-haired dog with a brindled coat and square-jawed muzzle developed in Germany