Other forms: boxers
Someone taking part in a sport in which two people punch each other with big padded gloves is a boxer. If you want to be a boxer, you'll need to build your arm strength and practice fast-moving footwork.
If you spend time training at a boxing gym, sparring in the ring with partners who dance around throwing jabs in your direction, you can call yourself a boxer. If your job involves putting things into cardboard boxes, you're another kind of boxer. A third meaning of this word is a smooth-coated, serious-faced breed of dog that's named for its habit of standing up and "boxing" with its paws when it plays with other dogs.