a calamitous event, esp. one occurring suddenly and causing great loss of life, damage, or hardship, as a flood, airplane crash, or business failure.

Obsolete . an unfavorable aspect of a star or planet.

noun

blessing , good fortune , good luck , miracle , prosperity , success , triumph , win , wonder

noun

act of god * , adversity , affliction , bad luck , bad news * , bale , bane , blight , blow , bust , calamity , casualty , cataclysm , catastrophe , collapse , collision , crash , debacle , defeat , depression , emergency , exigency , failure , fall , fell stroke , fiasco , flood , flop , grief , hard luck , harm , hazard , holocaust , hot water , ill luck , misadventure , mischance , misfortune , mishap , reverse , rock , rough , ruin , ruination , setback , slip , stroke , the worst , tragedy , undoing , upset , washout * , woe , accident , devastation , fatality