The word "calamity" is a noun that references a disaster or misfortune, especially one that causes serious damage and desolation, such as a flood or an earthquake. The word can also refer to any sort of mishap or accident.
"Calamity" entered the English language in the early 15th century and originally came from the Middle French word "calamite," which itself originated from the Latin "calamitas," meaning damage, loss, failure, disaster, misfortune or adversity. This word may have come from the Latin "incolumis," meaning "uninjured." The word can be pluralized as "calamities" and can also take the adjective form "calamitous." Other words with similar meanings to calamity include "disaster," "catastrophe," "cataclysm," "misfortune," "mischance" and "debacle."