gladiator vs combatant

gladiator and combatant both are nouns.

Word	Noun	Adjective	Verb	Adverb
gladiator	Yes	No	No	No
combatant	Yes	Yes	No	No

As nouns, combatant is a hypernym of gladiator; that is, combatant is a word with a broader meaning than gladiator:

gladiator: (ancient Rome) a professional combatant or a captive who entertained the public by engaging in mortal combat
combatant: someone who fights (or is fighting)

Other hypernyms of gladiator include battler, belligerent, fighter, scrapper.

gladiator (noun)	combatant (noun)
(ancient Rome) a professional combatant or a captive who entertained the public by engaging in mortal combat	someone who fights (or is fighting)
a professional boxer

gladiator (adjective)	combatant (adjective)
	engaging in or ready for combat