deep sleep — restful sleep
collocationB1IELTS 5+neutralcommon
A period of sleep when you are sleeping very well and your body and mind fully rest, usually without waking up easily.
Say it like a native
Textbook I was in a state of profound slumber.
Native I was in a deep sleep.
'Profound slumber' is literary; 'in a deep sleep' / 'fast asleep' is natural.
Pattern: in deep sleep; fall into deep sleep; be in a deep sleep
In use
- After a long day, I fell into a deep sleep and didn’t wake up until morning.daily life
- Getting enough deep sleep is important for your health because it helps your body recover and your mind feel clear the next day.IELTS speaking
Common mistake
✗ I was in deep sleep when you called.
✓ I was in a deep sleep when you called.
'In A deep sleep' needs the article.
Common collocations
deep sleep— fall into, a, in a, restful
Don't confuse it
'Light sleep' means you wake up easily; 'deep sleep' means you are hard to wake.