noun (n)

• (New Testament) day at the end of time following Armageddon when God will decree the fates of all individual humans according to the good and evil of their earthly lives(noun.time)

  Synonym:
  crack of doom, day of judgement, day of judgment, day of reckoning, end of the world, eschaton, judgement day, judgment day, last day, last judgement, last judgment
  

  source: wordnet30
• an unpleasant or disastrous destiny(noun.event)

  Synonym:
  day of reckoning, doom, end of the world
  

  source: wordnet30
• A day of sentence or condemnation; day of death.(noun)

  source: webster1913