centennary

A Roman looking at the number 100 would have called it centum, a compact little word that eventually scattered across modern vocabulary like coins from a broken purse. It gave English century, centennial, centenary—and even cent, the tiny coin that represents one hundredth of a dollar. The form centennary is an uncommon spelling variant of centenary, with an extra n that reflects the word’s connection to Latin centenarius, “consisting of a hundred.” The underlying idea is wonderfully stable: whether carved into a Roman inscription or printed on a modern anniversary banner, the word still points to the same milestone—one hundred turns of the calendar.