This is the 4953rd most frequent Japanese word.
秋季
"秋季" means "autumn season" or "fall."
Here, '秋季' refers to the autumn season in the context of an event or time period.
秋季のスポーツ大会が来月開催されます。
The autumn sports tournament will be held next month.
In this sentence, '秋季' is used to indicate the period of autumn when fruits are considered tastier.
果物は秋季に特に美味しいです。
Fruits are especially delicious during the autumn season.
Here, '秋季' marks the autumn season as the favorable time for observing the changing colors of leaves.