A chiongster is a person who aims to be the best at whatever they do. They always 'chiong' (speed/rush) to the finishing line, beating all their competitors to a pulp. These chiongsters tend to be nerdy.
The term chiongster can also refer to a person who loves the night life. In this case, the chiongster is a party animal who enjoys 'chionging' (partying).
S: Vivienne scored full marks on our last quiz.
K: What a chiongster!
I: I need a drink. Let's party!
S: I'm staying in. I'm a failed chiongster (party animal). I need to become a chiongster at the other end of the spectrum (nerd). Gonna hit the books!