A disaster, great mishap, catastrophe, violent upheaval.
→ A disaster, a catastrophe, a calamity, a debacle, and a cataclysm all refer to accidents, misfortunes, and sudden or violent changes. Let’s examine these words in order.
The negative prefix dis- denotes the absence or reverse of what follows: dislike is an absence of affection, discomfort is the absence of comfort, and disadvantage is the reverse of an advantage. In the word disaster, dis- combines with the Latin astrum, a star, to mean literally a reversal of the stars, an unfavorable horoscope; hence, an absence of luck, misfortune. Today disaster refers to a great misfortune involving ruinous loss of life or property. The sinking of the Titanic and the stock market crash of 1929 were disasters.
Catastrophe (kuh-TAS-truh-fee) combines the Greek kata-, down, with strophe, turn, to mean literally a down-turning. Originally catastrophe referred to the final turning point in a Greek tragedy where things go down the drain. Today catastrophe is used interchangeably with disaster, but properly disaster emphasizes the unforeseen, unlucky aspect of an event and catastrophe emphasizes its tragic and irreversible nature: The stock market crash of 1929 was a disaster for Wall Street, but it was only the beginning of the economic catastrophe we now call the Great Depression.
A calamity (kuh-LAM-i-tee) is an event that produces great distress, hardship, or misery, particularly on a personal level: The death of a loved one is always painful, but there is no greater calamity than the death of a child.
Debacle (di-BAH-kul) refers by derivation to a violent breaking up of ice in a river. It is often used today of any violent disruption or breakdown that leads to collapse or failure: “The breakup of the former Soviet Union was the debacle of communism”; “When Colosso Corporation laid off 20 percent of its workforce, company executives called it downsizing but employees called it a debacle.”
Our keyword, cataclysm, comes from a Greek verb meaning to wash away or dash over. In its original sense, still in good standing today, a cataclysm is a great flood, a deluge (DEL-yooj), specifically the biblical flood that inundated the earth for forty days and forty nights. (By the way, to inundate—pronounced INuhn-dayt or, less often, in-UHN-dayt—means to overflow or overwhelm.)
In current usage, cataclysm most often refers to a violent upheaval that causes great destruction and change. The adjective is cataclysmic (KAT-uh-KLIZ-mik). A cataclysmic event may be geological—such as a devastating earthquake, fire, or flood—or it may be social or political. Many would say that World War II was the greatest cataclysm in the tumultuous course of twentiethcentury history.
