Boxer/ˈbɑːksər/ Definition 1 of 2Pro Tip 1/3Sport Context Use 'boxer' for someone trained in boxing, not just any fighter. She trained to become a world-class boxer. Pro Tip 2/3Weight Classes 'Boxer' can imply different weight classes, important in boxing categories. He's a lightweight boxer aiming for the championship. Pro Tip 3/3Ring Sport The term 'boxer' is associated with a sport conducted in a ring. The boxer trained hard for the ring bout.