noun
General term for a season in nature, sports, TV, etc. Often used in compounds like 四季 (four seasons) or 雨季 (rainy season).
日本には四季がある。
Japan has four seasons.
サッカーの季が始まった。
The soccer season has started.
noun
Specifically a kigo (季語), a word or phrase that indicates the season in haiku poetry.
俳句では季を一つ入れるのが基本だ。
In haiku, it is basic to include one seasonal word.
noun
Rare standalone use; mainly appears in compounds like 一季 (one year) or 半季 (half a year).
「一季」は一年を意味する古い言い方だ。
「一季」 is an old expression meaning one year.