sempiternity

from WordNet (r) 3.0 (2006)

sempiternity
    n 1: the property of being perpetual (seemingly ceaseless) [syn:
         {perpetuity}, {sempiternity}]

from The Collaborative International Dictionary of English v.0.48

Sempiternity \Sem`pi*ter"ni*ty\, n. [L. sempiternitas.]
   Future duration without end; the relation or state of being
   sempiternal. --Sir M. Hale.
   [1913 Webster]