noun (n)

• the state of being absent(noun.state)

  Example:
  He was surprised by the absence of any explanation.
  

  source: wordnet30
• failure to be present(noun.act)

  Antonym:
  presence
  

  source: wordnet30
• the time interval during which something or somebody is away(noun.time)

  Example:
  He visited during my absence.
  

  source: wordnet30
• the occurrence of an abrupt, transient loss or impairment of consciousness (which is not subsequently remembered), sometimes with light twitching, fluttering eyelids, etc.; common in petit mal epilepsy(noun.state)

  Synonym:
  absence seizure
  

  source: wordnet30
• A state of being absent or withdrawn from a place or from companionship; -- opposed to presence.(noun)

  source: webster1913