就寝 (shūshin) means “going to bed” | MotiTan Japanese Dictionary

More examples

健康のため、毎日ほぼ同じ時刻に就寝することが大切です。ken kō no ta me mai nichi ho bo ona ji ji koku ni shū shin su ru ko to ga tai setsu de su

For your health, it is important to go to bed at nearly the same time every day.

Describes entering a place or state of rest for the night, with emphasis on the act of retiring rather than the whole period of sleep.

眠るために寝床に入ること。nemu ru ta me ni ne doko ni hai ru ko to

The Sino-Japanese compound combines 就 (shū, "settle into") and 寝 (shin, "sleep") to describe settling down to sleep.

In Japanese schedules and daily routines, 就寝 (shūshin) often labels a planned bedtime, so the word has a more formal tone than ordinary conversation.