mastiff

A dog of a large powerful breed developed in England as a guard dog, having a large head, short black muzzle, and short often fawn-colored coat.

A variety of dog of considerable antiquity.

A breed of large dogs noted for strength and courage. There are various strains, differing in form and color, and characteristic of different countries.

, any bat of the genus Molossus; so called because the face somewhat resembles that of a mastiff.

One of several large breeds of dog (such as bulldogs and Saint Bernards), often used as guard dogs

an old breed of powerful deep-chested smooth-coated dog used chiefly as a watchdog and guard dog