The Collaborative International Dictionary of English v.0.48:

Exuberance \Ex*u"ber*ance\, n. [L. exuberantia: cf. F.
   exub['e]rance.]
   The state of being exuberant; an overflowing quantity; a
   copious or excessive production or supply; superabundance;
   richness; as, an exuberance of joy, of fancy, or of foliage.

   Syn: Abundance; superabundance; excess; plenty; copiousness;
        profusion; richness; overflow; overgrowth; rankness;
        wantonness. See Abundance.
        [1913 Webster]

WordNet (r) 3.0 (2006):

exuberance
    n 1: joyful enthusiasm
    2: overflowing with eager enjoyment or approval [syn:
       exuberance, enthusiasm, ebullience]