In the Kirby series, a Star Warrior refers to someone who fights against the dark forces of Nightmare.
It is said that Nightmare created many monsters in his bid to rule the universe. One of these is said to be the Star Warriors. However, their noble way of thinking meant that they came to be opposed to their creator. The Star Warriors decided to rebel and form an Army to take on Nightmare, but sadly they lost against his superior power. Meta Knight was one of the few survivors.
Kirby is said to be a Star Warrior also (which would make him a creation of Nightmare).