late autumn; late fall
Refers to the end of autumn, typically around November in the modern calendar. Used in poetic or literary contexts.
In this late autumn season, I hope you are all doing well.
ninth month of the lunar calendar
Obsolete term corresponding to the ninth month of the old lunar calendar (roughly October in the modern calendar).
See also: 長月
In the old lunar calendar, the ninth month was also called 長月.