I am seeking some Greek/Roman words that embody the fighting spirit. Words that might be used to describe a valiant gladiator or warrior (similar to what the Japanese call bushido). Any suggstions?

Hoplite?

Do you want Greek or Italian words, or just words derived from those languages (and/or Latin...) in English?

Bushido is the code of the warrior, not the warrior himself. The linked Wiki article suggests chivalry, but that doesn't seem quite right given that chivalry doesn't carry the meaning of the warrior aspect anymore.