It's sleep
睡觉───sleep;是───yes
He was nodding off to sleep in an armchair.───他坐在扶手椅上打盹，睡着了。
REM sleep is termed 'active' sleep.───快速眼动睡眠称作“主动”睡眠。
His mind was in such a turmoil that he couldn't get to sleep.───内心的纷扰使他无法入睡.
Her brain was befogged by lack of sleep.───她因缺乏睡眠而头脑昏沉。
He awoke from his sleep in a cold sweat.───他从睡梦中醒来，浑身冒着冷汗。
A common superstition considered it bad luck to sleep in a room numbered 13.───(西方)一种普遍的迷信认为在13号房间睡觉是不吉利的.
I think I'll go upstairs and have a sleep.───我想上楼去睡一觉.
He mumbled some lame excuse about having gone to sleep.───他含含糊糊地找了个蹩脚的借口，想要解释自己为什么睡着了。
The noise awoke me from my sleep.
Walk groundly; talk profoundly; drink roundly; sleep soundly.
My efforts to go back to sleep proved futile.
I can't sleep in the daytime.
Now I shall go to sleep. Good night.