Sleep; the act or state of sleeping. The character appears both as a noun and in compounds (e.g., 寝る, 寝不足, 寝顔).
昨日は午後十時に寝た。
I went to bed at 10 p.m. yesterday.
赤ちゃんを寝かせるのが大変だ。
It's hard to get the baby to sleep.
寝不足で授業中に眠くなった。
I got sleepy during class because of lack of sleep.
彼の寝顔はとても穏やかだった。
His sleeping face looked very peaceful.