gladiator vs prizefighter

gladiator and prizefighter both are nouns.

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

As nouns, gladiator and prizefighter are synonyms defined as:

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