gladiator vs pugilist

gladiator and pugilist both are nouns.

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

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

Other hypernyms of gladiator include boxer.

gladiator (noun)	pugilist (noun)
(ancient Rome) a professional combatant or a captive who entertained the public by engaging in mortal combat	someone who fights with his fists for sport
a professional boxer