From Latin bisextilis (“containing an intercalary day”), from bisextus (“intercalary day”), from bis- (“two”) + sextus (“sixth”). In leap years there were two sixth days before March in the Roman calendar, thus the succession of days was ... 7 - 6 - 6* - 5 ...
- (UK) IPA: /bɪˈsɛks.taɪəl/
- (US) IPA: /bɪˈsɛks.taɪəl/, /bɑɪˈsɛks.tɑɪl/, /bɑɪˈsɛks.təl/, /bɪˈsɛks.təl/
Audio (US) (file)
- Having an extra day (of a leap year).
Derived terms 
bissextile (plural bissextiles)
- A leap year; A year having an extra day.
See also 
bissextile f sg
- feminine form of bissextil