The Collaborative International Dictionary of English v.0.48:

Liveliness \Live"li*ness\, n. [From Lively.]
   1. The quality or state of being lively or animated;
      sprightliness; vivacity; animation; spirit; as, the
      liveliness of youth, contrasted with the gravity of age.
      --B. Jonson.
      [1913 Webster]

   2. An appearance of life, animation, or spirit; as, the
      liveliness of the eye or the countenance in a portrait.
      [1913 Webster]

   3. Briskness; activity; effervescence, as of liquors.
      [1913 Webster]

   Syn: Sprightliness; gayety; animation; vivacity; smartness;
        briskness; activity. -- Liveliness, Gayety,
        Animation, Vivacity. Liveliness is an habitual
        feeling of life and interest; gayety refers more to a
        temporary excitement of the animal spirits; animation
        implies a warmth of emotion and a corresponding
        vividness of expressing it, awakened by the presence of
        something which strongly affects the mind; vivacity is a
        feeling between liveliness and animation, having the
        permanency of the one, and, to some extent, the warmth
        of the other. Liveliness of imagination; gayety of
        heart; animation of countenance; vivacity of gesture or
        conversation.
        [1913 Webster]

WordNet (r) 3.0 (2006):

liveliness
    n 1: general activity and motion [syn: liveliness,
         animation]
    2: animation and energy in action or expression; "it was a heavy
       play and the actors tried in vain to give life to it" [syn:
       liveliness, life, spirit, sprightliness]

Moby Thesaurus II by Grady Ward, 1.0:

150 Moby Thesaurus words for "liveliness":
   activity, adaptability, alacrity, animal spirits,
   animate existence, animation, anxiety, anxiousness, appetite,
   ardency, ardor, avidity, avidness, being alive, birth, bite,
   bounce, bounciness, breathless impatience, breeziness, brio,
   briskness, bubbliness, buoyance, buoyancy, capersomeness,
   cheerful readiness, coltishness, dash, eagerness, ebullience,
   ecstasy, effervescence, elan, elasticity, energy, enthusiasm,
   esprit, excitement, existence, extensibility, exuberance, fervency,
   fervidness, fervor, fire, flexibility, forwardness, friskiness,
   frolicsomeness, furor, fury, gaiety, gamesomeness, gayness, ginger,
   give, glow, gust, gusto, guts, having life, heart, heartiness,
   heat, hotness, immortality, impassionedness, impatience,
   impetuosity, impetus, joie de vivre, keen desire, keenness, kick,
   life, lifetime, living, long life, longevity, lustiness, mettle,
   moxie, nip, nippiness, passion, passionateness, pep, pepperiness,
   peppiness, perkiness, pertness, piquancy, piss and vinegar,
   pizzazz, playfulness, poignancy, promptness, punch, pungency,
   quickness, raciness, readiness, rebound, relish, resilience,
   resiliency, responsiveness, robustness, rollicksomeness,
   rompishness, savor, skittishness, snap, snappiness, soul, sparkle,
   spice, spiciness, spirit, spiritedness, spirits, sportiveness,
   sprightliness, spring, springiness, spriteliness, stretch,
   stretchability, stretchiness, tang, tanginess, tone, tonicity,
   tonus, vehemence, verve, viability, vigor, vim, vitality,
   vivaciousness, vivacity, vividness, warmth, warmth of feeling,
   zeal, zest, zestfulness, zip