A battler is someone who engages in a struggle or fight, often for a cause. A CONTENDER is someone who competes in a contest or battle, while a BRAWLER is someone who engages in a physical fight. A GLADIATOR is a professional FIGHTER in ancient Rome, while a COMBATANT is someone who takes part in a battle or war. A BOXER is someone who participates in the sport of boxing, while a duelist is someone who engages in a formal fight with another person. A BELLIGERENT is someone who is hostile and aggressive, while a CHAMPION is someone who has won a competition or title. A COMPETITOR is someone who takes part in a contest or game, while a CONTESTANT is someone who takes part in a competition. An ASSAILANT is someone who attacks another person, while a STRUGGLER is someone who is engaged in a difficult struggle. Finally, a FIGHTER is someone who engages in physical combat.