The corridor cleaning machines with circular furry discs on the underside.
This name must be unique to my school. As a group of us were engaged in some light vandalism of the sixth form common room, the head caretaker walked in and caught us.
Angry, but not having enough respect or guts to challenge us directly, he said "stop that, or I'll go and get Mike Webber". The idea of our Deputy Head, Mr Webber, having an informal first name didn't register, so there was a moment of confusion before someone asked "what's a kwebber?"
The only thing that made sense was that he was offering to tidy up our mess with his massive sandy-wheeled machine. So on we carried.