noun (n)

• a state or condition markedly different from the norm(noun.state)

  Synonym:
  aberrance, aberrancy, deviance
  

  source: wordnet30
• a disorder in one's mental state(noun.state)

  source: wordnet30
• an optical phenomenon resulting from the failure of a lens or mirror to produce a good image(noun.phenomenon)

  Synonym:
  distortion, optical aberration
  

  source: wordnet30
• The act of wandering; deviation, especially from truth or moral rectitude, from the natural state, or from a type.(noun)

  source: webster1913