A bulldog is a muscular, medium-sized dog breed with a distinctive appearance: a wrinkled face, pushed-in nose, wide-set legs, and a powerful build. Originally bred in England centuries ago, bulldogs got their name because they were used in a cruel sport called bull-baiting, where dogs fought bulls for entertainment. Thankfully, that practice was outlawed in the 1800s, and bulldogs today are known for being loyal, gentle companions rather than fighters.

Despite their somewhat grumpy expression, bulldogs are typically calm, friendly dogs who love being around people. They move with a characteristic waddle and are known for being stubborn but affectionate. Many schools and sports teams use the bulldog as their mascot because the breed symbolizes courage, determination, and toughness.

As an adjective, bulldog can describe a person who shows similar qualities. When someone has bulldog determination, they refuse to give up, no matter how difficult things get. A bulldog prosecutor might pursue a case relentlessly. Like the breed itself, calling someone a bulldog suggests they're tough, persistent, and won't back down from a challenge.