All the success definitions are defined by own individual. All the definitions mentioned in the paragraph earlier are alright. I would just like to add on that doing the things you like everyday is also a success in life. Doing something you are passionate about everyday will drive yourself towards to success too. Not necessary must be driving big car or living in a mansion.
Let me share a story.
Once there was a boy who likes shoes. He has a very strong passion in making shoes. He starts to make his very first shoes when he was kid. When he was in studying as fashion design in college, he worked in a factory as shoes cleaner to fund his education. He just so passionate about shoes designing and non-stop designing in his own style. During the early times when he just started his company, he is still infamous and that doesn't stop him from what he love. He just keep designing and making shoes until one day people start to recognize his work and he become a super famous ladies' shoes designer in the world. Do you thing this is also a success story? He just become success and famous by just doing what he passioned about everyday. Even though there are a lot of noise beside him to influence him from quiting what he is doing but he just ignored them and continue to do what he loves to.
So, have you found the things you love to do? Are you doing the things you like everyday? Are you defining your own success? Find what you really love to do and do it everyday!
To me success is just a very simple theory, Do what you passion and passion on what you do!