Pass means, "No thank you, I'm not interested." Example: "Would you like some more pie? No thanks, I'll pass, I am already too full to eat more."

It means the person does not want to answer or give a comment about something, so the conversation can move on to another person. It is said when a person is too shy to answer, too afraid to answer, or may not have the answer.

It means they don't want to do whatever they were asked.