Wan-tew-tree silence

n.

A game played in school classrooms when the teacher went out on a message.

Let Lawrence Muck translate it to posh English for you
Lawrence Muck

Greetings and felicitations. Would you like me to translate 'Wan-tew-tree silence' in use for you?

One, two, three, silence! The first to utter a sound shall be set upon by the entire class.