What is a Champion?

I agree with both the OP and the other responses already here as I write this. There's definitely not just a single definition.

Lately I've been reading and hearing about the roots of people, friends and strangers, and the journeys they've found themselves on after things that impacted them--not always good or safe things, either. So that's influencing my response right now to add in these facets:

A champion is also. . .

• Someone who doesn't let adversity turn them into an adverse human being, but instead chooses to keep going, keep learning, and keep sharing what they've done and learned to help others.
• Someone who gives without thought or care to what they'll get in return. There is no hidden agenda.
• Someone who very probably would never give the word 'champion' to themselves because to them, they're just doing their jobs, or just sharing information.

Whether it's pushing forward with a product you sincerely know will help people, even though it means months of hard work on top of an organizational culture change (and a lot of moans and groans), or turning on that "Aha!" light for someone who's been struggling with a task, being able to turn dross into gold is an admirable and enviable trait. It's being a champion.