Definition specifications, or dspecs, are a systematic way of naming definitions. The dspec system includes all kinds of definitions provided in LispWorks, and can be extended to include definers that you add.
Most named definitions are global, but local functions can have names, and some of the operations described here can be applied to them as well.
Here are three examples of dspecs:
A dspec is simply a name: you can operate on it even if the thing named does not currently exist.
LispWorks User Guide and Reference Manual - 20 Sep 2017