(n.) One who fights in single combat.

battler belligerent belted knight bickerer blade bravo brawler bully bullyboy combatant competitor contender contestant disputant enforcer fencer feuder fighter fighting cock foilsman gamecock gladiator 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