Search Result for "irreversibility": 
Wordnet 3.0

NOUN (1)

1. the quality of being irreversible (once done it cannot be changed); 



The Collaborative International Dictionary of English v.0.48:

Irreversibility \Ir`re*vers`i*bil"i*ty\, n.
   The state or quality of being irreversible; irreversibleness.
   [1913 Webster]


WordNet (r) 3.0 (2006):

irreversibility
    n 1: the quality of being irreversible (once done it cannot be
         changed) [ant: reversibility]