The Collaborative International Dictionary of English v.0.48:
Transience \Tran"sience\, Transiency \Tran"sien*cy\, n. The quality of being transient; transientness. [1913 Webster]WordNet (r) 3.0 (2006):
transiency n 1: an impermanence that suggests the inevitability of ending or dying [syn: transience, transiency, transitoriness]