Answer: doomsday

AnswerCrossword Clue
DOOMSDAY

December 21, 2012 event

DOOMSDAY

End of the world

DOOMSDAYThe end of the world
DOOMSDAY

End of the world as we know it

DOOMSDAY
Judgment time
DOOMSDAY
The end of time
DOOMSDAYMaximally calamitous
DOOMSDAYLast Judgment.
DOOMSDAYRelative of Armageddon
DOOMSDAYTime of judgment
DOOMSDAYFinal Judgment
DOOMSDAYWorld's end