fighting with real swords; real sword fight
Literal historical meaning: a duel or battle using actual blades, not practice swords.
Scenes of real sword fights are often depicted in period dramas.
serious contest; game played in earnest; all-out effort
Figurative extension: any competition or confrontation where participants give their all, as if fighting with real swords.
The next match will be a serious contest.
I debated with him in all seriousness.