cut-out

 A species of switch for changing the current from one circuit to another, or for shortening a circuit.  [1913 Webster]

 Something cut out from another object, especially a piece of thick paper or cardboard with a picture on it (as of a person or other object), embedded in a larger sheet of paper and having perforations around the edges of the figure to allow easy removal from the larger sheet.  [PJC]

 A valve in the exhaust system of an internal combustion engine which, when activated, permits the exhaust gases to bypass the muffler.  [PJC]