The Collaborative International Dictionary of English v.0.48:

Dionysian \Di`o*ny"sian\, a.
   Relating to Dionysius, a monk of the 6th century; as, the
   Dionysian, or Christian, era.
   [1913 Webster]

   Dionysian period, a period of 532 years, depending on the
      cycle of the sun, or 28 years, and the cycle of the moon,
      or 19 years; -- sometimes called the Greek paschal
      cycle, or Victorian period.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Dionysian
    adj 1: of or relating to or worshipping Dionysus