Source : Webster's Revised Unabridged Dictionary (1913)

Transience \Tran"sience\, Transiency \Tran"sien*cy\, n.
   The quality of being transient; transientness.

Source : WordNet®

transiency
     n : an impermanence that suggests the inevitability of ending or
         dying [syn: {transience}, {transitoriness}]