Source : Webster's Revised Unabridged Dictionary (1913)

Talkative \Talk"a*tive\, a.
   Given to much talking.

   Syn: Garrulous; loquacious. See {Garrulous}. --
        {Talk"a*tive*ly}, adv. -- {Talk"a*tive*ness}, n.

Source : WordNet®

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