The Collaborative International Dictionary of English v.0.48:

Festivity \Fes*tiv"i*ty\, n.; pl. Festivities. [L. festivitas:
   cf. F. festivit['e].]
   1. The condition of being festive; social joy or exhilaration
      of spirits at an entertaintment; joyfulness; gayety.
      [1913 Webster]

            The unrestrained festivity of the rustic youth.
                                                  --Bp. Hurd.
      [1913 Webster]

   2. A festival; a festive celebration. --Sir T. Browne.
      [1913 Webster]

WordNet (r) 3.0 (2006):

festivity
    n 1: any joyous diversion [syn: celebration, festivity]