noun (n)

• the process of rendering inactive(noun.process)

  Example:
  The gene inactivation system.
  Thermal inactivation of serum samples.
  

  Antonym:
  activation
  

  source: wordnet30
• breaking up a military unit (by transfers or discharges)(noun.act)

  Synonym:
  deactivation
  

  source: wordnet30