Does "up" mean "ready" in this context?
Native speaker’s answer
Rebecca
Good guess! To be "up" for something means that you are willing to do something. In this case, "are you up for this?" means "are you willing to do this?" Alternatively, you can use the expression "are you down [for something]?" Both are informal expressions with the same meaning. Ex. Are you up for pizza tonight? Ex. Are you down for a movie this weekend?