What's a Kabbash?

someone called to ask about the Megillah reading. Here is how the convo went:

him: this is a very important day, you know
me: I know
him: it's the day you put the Kabbash on the devil
me: umm...
him: you know that, right? b/c haman is the devil. you have to stamp out his voice.
me: yep....right....
him: now, what are you reading from? are you reading from the Koren version?
me: we're reading from a scroll
him: oh, not the koren version?
me: no

it went on from there, but that's the funny part. the rest was boring.....relative to that....