The Collaborative International Dictionary of English v.0.48:
Obsoleteness \Ob"so*lete*ness\, n. 1. The state of being obsolete, or no longer used; a state of desuetude. [1913 Webster] 2. (Biol.) Indistinctness; want of development. [1913 Webster]WordNet (r) 3.0 (2006):
obsoleteness n 1: the property of being out of date and not current [syn: obsoleteness, superannuation]