When it comes to finding synonyms for the term "junkyard dog," several options come to mind. Other pet names that refer to a dog's toughness and tenacity include "pitbull," "rottweiler," and "bulldog." Meanwhile, terms like "watchdog," "guard dog," and "attack dog" highlight the protective qualities of these animals. Other colorful phrases that can be used to replace "junkyard dog" include "street fighter," "brawler," and "rough-and-tumble." No matter which term is used, the underlying meaning remains the same: a tough and formidable being that is not easily intimidated.