Source : Webster's Revised Unabridged Dictionary (1913)

Toothsome \Tooth"some\, a.
   Grateful to the taste; palatable. -- {Tooth"some*ly}, adv. --
   {Tooth"some*ness}, n.

         Though less toothsome to me, they were more wholesome
         for me.                                  --Fuller.

Source : WordNet®

toothsomeness
     n : extreme appetizingness [syn: {delectability}, {deliciousness},
          {lusciousness}]