ummmmmmmm
Chorused, often in crescendo, at anyone breaking those petty primary school rules such as underlining the date but not the title. "Ummmmm, I'm telling of yooooou."
written by Ho*ly*, approved by Log

You could escape being told on by shouting BUM loudly while the 'ummmmm' was still going on, and before the rest started.
Doing it in lessons was a calculated gamble on which would get you into less trouble - being told on, or shouting 'bum'.
written by excluded pupil, A , approved by Log