1. In the Gregorian calendar, a year with 366 days including 29th February; usually any year divisible by 4 is a leap year, with the exception that centenary years are not leap years unless divisible by 400
   "2020 was a leap year with 366 days";
   - leap year, intercalary year, bissextile year

Type of: twelvemonth [archaic], year, yr