Gladiator

Noun

 * 1) (in ancient Rome) a person (professional or slave) who entertained the public by engaging in mortal combat with another, or with a wild animal
 * 2)  a disputant in a public controversy or debate
 * 3) a professional boxer

Thesaurus
battler, belligerent, belted knight, bickerer, blade, bravo, brawler, bully, bullyboy, combatant, competitor, contender, contestant, disputant, duelist, enforcer, fencer, feuder, fighter, fighting cock, foilsman, gamecock, goon, gorilla, hatchet man, hood, hoodlum, hooligan, jouster, knight, militant, plug-ugly, quarreler, rioter, rival, rough, rowdy, ruffian, sabreur, scrapper, scuffler, squabbler, strong arm, strong-arm man, strong-armer, struggler, swashbuckler, sword, swordplayer, swordsman, thug, tilter, tough, tussler, wrangler