- calamity, catastrophe, disaster, tragedy, cataclysm - an event resulting in great loss and misfortune; "the whole city was affected by the irremediable calamity"; "the earthquake was a disaster"
--1 is a kind of misfortune, bad luck
--1 has particulars:act of God, force majeure, vis major, inevitable accident, unavoidable casualty; apocalypse; famine; kiss of death; meltdown; plague; visitation - catastrophe, disaster - a state of extreme (usually irremediable) ruin and misfortune; "lack of funds has resulted in a catastrophe for our school system"; "his policies were a disaster"
--2 is a kind of adversity, hardship, hard knocks
- catastrophe, cataclysm - a sudden violent change in the earth's surface
--3 is a kind of geological phenomenon
--3 has particulars: nuclear winter