Leap is usually the term assigned to the year that has 366 days.
the prefix bi it refers to the repetition of something, in this case, by being followed by the ordinal number “sixth”, it means its repetition, that is, twice the number six.
It is also usual to mention the 29th day of the month of February as a leap, in reference to this particularity that characterizes the so-called “leap year”.
From a figurative sense, this term can also be used to qualify the scarce periodicity of something, such as an activity, for example.
The expression “leap poet”, for example, is usually common in Brazil to refer to a poet who publishes his literary texts occasionally, with scarcity.
Leap year
It is when the year has 366 days, that is, one day longer than normal.
Leap years (almost always) occur at four-year intervals, when the month of February is given an extra day: February 29th. According to the Gregorian calendar, a year is leap year when it is divisible by 4. It is not considered leap when it is divisible by 100, unless it is divisible by 400.
Leap years were created with the aim of regulate the annual calendar with the Earth's translation, preventing seasonal events related to the seasons from being altered, for example.
Find out more about the meaning of leap year.