Noun
A dog of a medium to large, predominantly white breed with short, coarse coat, squarish flat skull, and powerful jaws and hind legs, originally bred as a protection and defense dog against the hostile frontier of early Spanish Florida. They are the closest descendants of the old Spanish guard and war dogs brought by settlers and conquistadors to Argentina and Spanish Florida.
(Britain) A type of farm utility dog.
Source: en.wiktionary.org