What does cynical mean, and how do i know if i am it?

It basically means to believe the worst of human nature. If you're cynical about a friend's boy/girlfriend, it means that, despite what may actually happen, you believe it's no-no right from the start. Cynics really believe in themselves (ie everyone else is wrong, I'm right), so even if someone told you that were cynical, you prob wouldn't believe them.