(n.) A violent catastrophe involving sudden changes of the earth's surface; a social upheaval; a deluge\; an extensive overflow or sweeping flood of water\.

accident alluvion alluvium apoplexy bloodless revolution blow bouleversement breakdown breaking up breakup calamity casualty cataract catastrophe cave cave-in clean slate clean sweep climax collapse collision computer revolution contretemps convulsion counterrevolution crack-up crash debacle deluge diastrophism disaster engulfment fit flood flooding grief ill hap inundation misadventure mischance misfortune mishap nasty blow overflow overflowing overrunning overthrow overturn palace revolution paroxysm pileup pour quake radical change revolt revolution revolutionary war revulsion shipwreck shock smash smashup spasm spate spill spillage staggering blow striking alteration stroke submersion subversion sweeping change tabula rasa technological revolution temblor the Deluge the Flood tidal wave torrent total change total loss tragedy transilience tsunami upheaval upset violent change washout whelming wrack wreck