* μαχητής (machētēs): This is probably the closest single word, meaning "fighter" or "combatant." It emphasizes the act of fighting.
* στρατιώτης (stratiōtēs): This means "soldier" and is a good choice if referring to a professional warrior within an army.
* ἀνδρεῖος (andreios): This means "brave," "manly," or "courageous," and could be used to describe a warrior's character rather than their profession. It's not a direct translation but often implies warrior-like qualities.
* ἥρως (hērōs): This translates to "hero," often a legendary or demigod warrior.
The best word to use depends heavily on the specific nuance you wish to convey.