What does HERO mean?

noun

1. a man distinguished by exceptional courage and nobility and strength“RAF pilots were the heroes of the Battle of Britain”
2. the principal character in a play or movie or novel or poem
3. someone who fights for a cause
4. (classical mythology) a being of great strength and courage celebrated for bold exploits; often the offspring of a mortal and a god
5. a large sandwich made of a long crusty roll split lengthwise and filled with meats and cheese (and tomato and onion and lettuce and condiments); different names are used in different sections of the United States