亥がい月げつがいげつじ字FuriganaMeanings1nountenth month of the lunar calendarobsolete termObsolete term from the traditional Japanese lunar calendar. The month name uses the Earthly Branch 亥 (Boar), which was associated with the tenth month in the directional-month system. Not used in modern calendar contexts.旧きゅう暦れきでは亥がい月げつは冬ふゆの始はじまりにあたる。In the old lunar calendar, the Boar Month marked the beginning of winter.