middleweight vs gladiator

middleweight and gladiator both are nouns.

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

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

Other hypernyms of middleweight include prizefighter.

middleweight (noun)	gladiator (noun)
a professional boxer who weighs between 155 and 160 pounds	(ancient Rome) a professional combatant or a captive who entertained the public by engaging in mortal combat
a wrestler who weighs 172-192 pounds	a professional boxer
an amateur boxer who weighs no more than 165 pounds