noun (n)

• an unfortunate state resulting from unfavorable outcomes(noun.state)

  Synonym:
  ill luck, misfortune, tough luck
  Antonym:
  good fortune, good luck, luckiness
  

  source: wordnet30
• an unpredictable outcome that is unfortunate(noun.phenomenon)

  Example:
  If I didn't have bad luck I wouldn't have any luck at all.
  

  Synonym:
  mischance, mishap
  

  source: wordnet30
• unnecessary and unforeseen trouble resulting from an unfortunate event(noun.event)

  Synonym:
  misfortune
  

  source: wordnet30