glad·i·a·tor 
(glădē-ā′tər)
(glădē-ā′tər)n.
1. A person, usually a professional combatant, a captive, or a slave, trained to entertain the public by engaging in mortal combat with another person or a wild animal in the ancient Roman arena.
2. A person engaged in a controversy or debate, especially in public; a disputant.
3. Sports A professional boxer.
[Middle English, from Latin gladiātor, from gladius, sword, of Celtic origin; akin to Old Irish claideb.]
glad′i·a·tori·al (-ə-tôrē-əl) adj.