godan verb (-ru), intransitive verb
Poetic and literary verb for the sun setting; in modern Japanese, 沈む (しずむ) or 暮れる (くれる) are far more common. The kanji 没る is rare and may not be recognized by many readers.
See also: 入る
The scene of the evening sun setting behind the western mountains was often composed in old waka poems.
「日が没る」という表現は、現代ではほとんど使われない。
The expression '日が没る' is hardly used in modern times.