noun
first day of winter; beginning of winter
One of the 24 solar terms (二十四節気), marking the start of winter around November 7–8. Used in calendars and seasonal references.
See also: 二十四節気
立冬を過ぎると、朝晩は冷え込むようになる。
After the first day of winter, mornings and evenings become chilly.
今年の立冬は十一月七日です。
This year, the first day of winter is November 7th.
From Chinese lìdōng, combining 立 (to stand, establish) and 冬 (winter). The term was adopted into Japanese as part of the traditional East Asian calendar system.