(じゅくすい)

じゅくすい
noun, verb (suru)
deep sleep, sound sleep
1. deep sleep, sound sleep
Sleeping deeply and soundly without waking, resulting in a well-rested state.
昨夜(ゆうべ)熟睡(じゅくすい)できた。
I slept soundly last night.
(つか)れていたので、熟睡(じゅくすい)してしまった。
I was so tired that I fell into a deep sleep.
(しず)かな環境(かんきょう)のおかげで、(ひさ)しぶりに熟睡(じゅくすい)することができた。
Thanks to the quiet environment, I was able to sleep soundly for the first time in a while.

USAGE:
Often used with できる (熟睡(じゅくすい)できた = I slept well) or する (熟睡(じゅくすい)した = I slept deeply). Implies a particularly restful, uninterrupted sleep — more than just ()る (to sleep) or (ねむ)る (to fall asleep).

SIMILAR WORDS:

  • 爆睡(ばくすい): sleeping like a log (more casual, emphasizes sleeping so hard you can't be woken)
  • 熟睡(じゅくすい): deep, quality sleep (more neutral/formal)

COMMON COLLOCATIONS:

  • 熟睡(じゅくすい)する: to sleep soundly
  • 熟睡(じゅくすい)できない: can't sleep deeply
  • 熟睡(じゅくすい)できる環境(かんきょう): an environment conducive to deep sleep

Related Words