A bully-rook is basically a old ass way of saying some is your homie or your best friend dating all the way back to mideval times, it can also be used in the context of a person or a group of people being childish or disruptive.
"Hey do you need help fixing your produce stand? I have a bully-rook by the name of Arthur who can help you out across the road!"

"Look out for those bully-rooks over there... They're always causing trouble in town you would want to get mixed up in their infantile rubbish"
by Butter Toons November 17, 2021
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