- containing or noting the extra day of leap year: The years 1980 and 1984 were both bissextile.
Origin of bissextile
Examples from the Web for bissextile
Historical Examples of bissextile
This fourth year was denominated Bissextile, because the sixth day before the Kalends of March was reckoned twice.Letters on Astronomy
Can we therefore believe that the Egyptians before this period were ignorant of the bissextile intercalation?
The bissextile is known to have been used by the Mayas, Tzendals, and Quichés, and it was probably common.Ancient America, in Notes on American Archaeology
John D. Baldwin
The fourth year was bissextile, and the dominical letters were F, E; the following year D, and so on.
- (of a month or year) containing the extra day of a leap year
- a rare name for leap year
Word Origin for bissextile
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.