Definitions for knocking
the sound of knocking (as on a door or in an engine or bearing)
"the knocking grew louder"
An act in which something is knocked on, or the sound thus produced
a beating; a rap; a series of raps
The Roycroft Dictionary
A slow but sure way of putting the skids under your prospects. Push in the door softly, and all things are yours--knock and nothing shall be opened unto you.