What is success?

I've been watching an interesting program on the History channel about Albert Einstein, and it made me ask the question...what is success? Surely Einstein or Beethoven or Monet or Florence Nightingale or Abraham Lincoln or Winston Churchill or Franz Kafka were successes. But did they all know it? Did people realize it during their time? Who will be successful 50 years from now? Or 100 years from now?

I looked up the definition: "the favorable or prosperous termination of events or endeavors; the attainment of wealth, position, honors, or the like."

While other positive events or honors are linked to it, clearly wealth is seen as a big part of success. But is it? Many famous artists or authors or composers weren't identified in their time. The importance of a scientific theory or art often isn't realized at first. There surely are levels of success, but I believe the successes that change the world often aren't known when the person responsible is alive. Yes, Bill Gates is successful in his work with computers, but not as successful as those who envisioned how computers would be used.