Liberal Dictionary English Dictionary
adjective
- containing or noting the extra day of leap year: The years 1980 and 1984 were both bissextile.
noun
adjective
- (of a month or year) containing the extra day of a leap year
noun
- a rare name for leap year
1580s (n.); 1590s (adj.), in reference to Roman leap year, from Late Latin (annus) bissextilis “leap year,” literally “the twice sixth-day,” because the sixth day before the Calends of March was doubled.