Wormhole

 WORMHOLE n. A location in a monitor which contains the address of a
       routine, with the specific intent of making it easy to substitute a
       different routine. The following quote comes from "Polymorphic
       Systems", vol. 2, p. 54: "Any type of I/O device can be
       substituted for the standard device by loading a simple driver routine
       for that device and installing its address in one of the monitor's
       `wormholes.'* ---------- *The term `wormhole' has been used to
       describe a hypothetical astronomical situation where a black hole
       connects to the `other side' of the universe. When this happens,
       information can pass through the wormhole, in only one direction, much
       as `assumptions' pass down the monitor's wormholes."