[Moxie.]

I've found that the best way to try to explain it to people is to compare it to a situation where they might have felt a bit of anxiety. For example, you could say "You know that feeling you get in the pit of your stomach before you have to make a presentation in class? The butterflies, the nerves, the fear that something is going to go terribly wrong? Imagine feeling like that all the time. That's what anxiety is." By comparing it to a feeling that the person you're explaining it to may have felt in the past, they're more likely to understand it.