This is the 7543rd most frequent Japanese word.
冬将軍
"Winter General"; a personification of harsh winter weather.
Here, '冬将軍' is personified, likening the cold winter to an enemy one prepares to confront.
冬将軍との戦いに備えて、暖かいコートを買った。
I bought a warm coat to prepare for the battle against General Winter.
In this example, '冬将軍' suggests the particularly harsh conditions of this year's winter compared to other years.
今年の冬将軍は特に厳しいと思う。
I think this year's General Winter is especially severe.
In this sentence, '冬将軍' is used metaphorically to represent the strong cold and freezing weather typical of winter.