doomsday

Noun

• an unpleasant or disastrous destiny
  • everyone was aware of the approaching doom but was helpless to avoid it
    
  • that's unfortunate but it isn't the end of the world
    

• (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

Related words

• Synonyms: 
  doom , day of reckoning , end of the world