Answer: cataclysm

AnswerCrossword Clue
CATACLYSMDisaster
CATACLYSMGreat upheaval.
CATACLYSMSocial or political upheaval.
CATACLYSMViolent change
CATACLYSMWhat M. learned
CATACLYSMLarge-scale disaster
cataclysmany violent upheaval, especially one of a social or political nature.
cataclysmA large-scale and violent event in the natural world
cataclysmA sudden violent upheaval, esp. in a political or social context
cataclysma great flood or other major disaster