Literary or classical term for a period of moral decline or a world in decay. Rare in modern Japanese; mainly found in older texts or elevated prose.
古典文学では、季世の到来を嘆く表現が見られる。
In classical literature, one finds expressions lamenting the arrival of a degenerate age.
Borrowed from Chinese 季世, in which 季 means “last” or “final,” hence an age regarded as the declining end of an era.