Bissextile (noun)
bi-secs-tile
The leap year.
First recorded in 1585–95 and from the word bissextus, which refers to February 29th. Bissextus means literally “the second sixth,” so called because the 6th day before the first day of March in the ancient Roman calendar appeared a second time once every leap year.
Example sentences
“The extra day in a bissextile helps keep the calendar in sync with the solar year.”
