Source : Webster's Revised Unabridged Dictionary (1913)

Quodlibet \Quod"li*bet\, n. [L., what you please.]
   1. A nice point; a subtilty; a debatable point.

            These are your quodlibets, but no learning. --P.
                                                  Fletcher.

   2. (Mus.) A medley improvised by several performers.

Source : WordNet®

quodlibet
     n : an issue that is presented for formal disputation