It's not my definition. It's the definition of the world in the English language. It's all about the admiration, not the person itself. It's funny that you mention Hollywood since the principal male character in a movie is by definition a hero.
hero
he·ro
[heer-oh] Show IPA
noun, plural he·roes; for 5 also he·ros.
1. a man of distinguished courage or ability, admired for his brave deeds and noble qualities.
2. a person who, in the opinion of others, has heroic qualities or has performed a heroic act and is regarded as a model or ideal.
3. the principal male character in a story, play, film, etc.