coaster

   1.  Unuseable  CD  produced  during  failed  attempt  at  writing  to
   writeable   or  re-writeable  CD  media.  Certainly  related  to  the
   coaster-like shape of a CD, and the relative value of these failures.
   "I made a lot of coasters before I got a good CD."

   2.  Useless CDs received in the mail from the likes of AOL, MSN, CI$,
   Prodigy, ad nauseam.

   In the U.K., beermat is often used in these senses.

[glossary]
[Reference(s) to this entry by made by: {coaster toaster}]