".. huh?"

That's a good question. Or at the very least a surprising question, since Madoka looks like she totally didn't see it coming. At least the surprise stops her panic for the moment..

"Well.. magic is when you cast spells and those kinds of things, right? Like you sometimes see in--" 'cartoons on TV', she almost says, but then realises that'd just be more confusing for him. "-- in stories! Like what witches and good fairies use! People don't use that in real life."