Source : Webster's Revised Unabridged Dictionary (1913)

Loquaciousness \Lo*qua"cious*ness\, n.
   Loquacity.

Source : WordNet®

loquaciousness
     n : the quality of being wordy and talkative [syn: {garrulity},
         {garrulousness}, {loquacity}, {talkativeness}]