Mastiff, a name for a European and an Asiatic breed of dogs of large size and noble appearance. The origin of the English mastiff is lost in obscurity. The original breed has been much modified by crossing with the St. Bernard, the boarhound, and the bull-dog. The average height of the English mastiff at the shoulder "is from 28 to 30 inches, and the chest girth should be at least a third as much. The body is long and cylindrical, with a smooth coat, the limbs stout and strong, the feet round and close, and the tail thick, but not bushy. The ears and lips are pendulous, and dogs are now bred with the head much shorter, the muzzle more nearly square than was the fashion ten years ago. The general colour is fawn, with dark or black muzzle, ears, and feet. Dogs of the old breed were fierce and courageous; the mastiffs of the present day are kept as companions and watch-dogs. The Tibet Mastiff is a little smaller, and has a rough coat; and similar dogs occur in other parts of Asia.