A boxer is someone who competes in the sport of boxing, fighting an opponent with gloved fists inside a roped square called a ring. Boxers train for years to develop speed, power, footwork, and defensive skills. Famous boxers like Muhammad Ali and Joe Louis became cultural heroes, admired for their athletic ability, courage, and determination.

The sport has strict rules: boxers can only strike above the waist with closed fists, matches are divided into timed rounds, and referees stop fights if someone gets hurt.

The word also refers to a medium-sized dog breed with a square head, short coat, and energetic personality. Boxer dogs were originally bred in Germany as working dogs. They're known for being loyal, playful, and protective of their families, making them popular pets despite their somewhat intimidating name.