noun (n)

• a literary work based on the imagination and not necessarily on fact(noun.communication)

  source: wordnet30
• a deliberately false or improbable account(noun.communication)

  Synonym:
  fable, fabrication
  

  source: wordnet30
• The act of feigning, inventing, or imagining; as, by a mere fiction of the mind.(noun)

  source: webster1913