obsolescence
1. [ noun ] the process of becoming obsolete; falling into disuse or becoming out of date
Examples:

"a policy of planned obsolescence"

Related terms: degeneration obsolesce
2. [ noun ] the property of being out of date and not current
Synonyms: superannuation obsoleteness
Related terms: oldness superannuate
Similar spelling:   obsolesce
  obsolescent
  obsoleteness