adversary
battler
belligerent
belted knight
bickerer
blade
bravo
brawler
bully
bullyboy
carouser
combatant
competitor
contender
corrival
cutup
disputant
duelist
emulator
enforcer
entrant
fencer
feuder
fighter
fighting cock
foilsman
frisker
frolicker
funmaker
gamboler
gamecock
gladiator
goon
gorilla
hatchet man
hood
hoodlum
hooligan
jouster
juster
knight
litigant
merrymaker
militant
opponent
participant
decongestant