a) the act of specifically raping a virgin teen girl in the anus

b) arriving somewhere unexpectedly, when they least expect you.
sociologist of criminal behavior, (visiting the cemetery of Marion State Prison, Illinois): Ghost Poinsalet, I hear you are famous, even among ghosts, in this cemetery. What have you been incarcerated, and executed for, 27 years ago?

ghost of Matthew Poinsalet (character from Dead Man Walking): Sir, it was for knocking at your back door, definition b), to the house of 2 virgin teen girls, then committing knocking at your back door, definition a), and then finally murdering my victims.

sociologist (under his breath): How atrocious, may we condemn all child rapists and murderers to the electric chair, Amen.
by Sexydimma June 1, 2015
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It is an old irish saying meaning to be fed well enough to become fat. Ex: Your sides are fat enough to cover your backbone.
Man: Aye lad, have ye got your sides o'er your back yet?
Boy: Yes sir I have eaten my fill.
by Veritazium May 6, 2021
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