autumn season; fall season
Refers to the autumn/fall season, especially in formal, written, institutional, or event names such as 秋季大会 and 秋季講習.
The autumn tournament will be held in October.
I signed up for the university's autumn courses.
The autumn tournament was held in the gym.
I decided to attend the autumn course.
They are selling an autumn-limited cake.
秋季 designates the autumn season in formal contexts, while 春季 designates the corresponding spring season, and the two are often paired in event names like 春季大会 and 秋季大会.
秋季 refers to the autumn season itself, whereas 秋期 (same reading) refers to the autumn term or period, such as a school semester or course period.
autumnal imperial ancestor worship ceremony
Sino-Japanese compound of 秋, meaning autumn, and 季, meaning season.