Websters 1828 Dictionary defines a Leap-Year as:
LE'AP-YEAR, n. a year containing 366 days; every fourth year, which leaps over a day more than a common year. Thus in common years, if the first day of March is on Monday, the present year, it will, the next year, fall on Tuesday, but in leap-year it will leap to Wednesday; for leap-year contains a day more than a common year, a day being added to the month of February.
There are many different traditions associated with leap year but one that I found most mirth provoking was that Leap Year has traditionally been the one time when a women could propose marriage.
Tradition says that as far back as the 5th century in the Emerald Isle of Ireland, St. Bridget complained to good St. Patrick of the inequality of women having to wait to be asked for their hands in marriage. And, according to legend, St. Patrick said that henceforth on the February 29 of each Leap Year, a lady could do the asking!