Source : Webster's Revised Unabridged Dictionary (1913)

Vivacity \Vi*vac"i*ty\, n. [L. vivicitas: cf. F. vivacit['e].]
   The quality or state of being vivacious. Specifically:
   (a) Tenacity of life; vital force; natural vigor. [Obs.]

             The vivacity of some of these pensioners is little
             less than a miracle, they lived so long. --Fuller.
   (b) Life; animation; spiritedness; liveliness; sprightliness;
       as, the vivacity of a discourse; a lady of great
       vivacity; vivacity of countenance.

   Syn: Liveliness; gayety. See {Liveliness}.

Source : WordNet®

vivacity
     n : characterized by high spirits and animation