gladiator â(plural gladiators). ( 1 in ancient Rome) A person (professional or slave) who entertained the public by engaging in mortal combat with another, or with a wild animal.( 2 by extension) A disputant in a public controversy or debate. 3  A professional boxer.oun [edit]. gladiator â(plural gladiators). ( 1 in ancient Rome) A person (professional or slave) who entertained the public by engaging in mortal combat with another, or with a wild animal. ( 2 by extension) A disputant in a public controversy or debate. 3  A professional boxer.