also: はつふゆ
early winter
Refers to the beginning of winter, typically around November in the modern calendar. Used both as a noun and adverbially.
The early winter wind feels cold.
In early winter, the mountains receive their first snow.
tenth month of the lunar calendar
Obsolete term referring to the tenth month of the traditional lunar calendar, roughly corresponding to early winter.
In the old lunar calendar, 初冬 referred to the tenth month.