"dreamless sleep" is a correct and usable phrase in written English.
You can use it to refer to sleep that is uninterrupted or free of dreams. For example, "After a long and tiring day, she welcomed a dreamless sleep."
I can picture being in dreamless sleep quite easily.
When you're in dreamless sleep, you're not imagining or experiencing anything.
There is nothing that it's like to be in dreamless sleep.
Well, should we conclude, therefore, so nobody really believes that they're ever in dreamless sleep?
Of course you believe that at times you're in dreamless sleep.
It was for that I kept the house bare; the quiet catharsis of dreamless sleep.
Goes back home after her adventure and falls off into a dreamless sleep.
Under the branches of a shrub, I curled up and surrendered to a dreamless sleep.
Afterward, in our hotel room, I fell into a deep and dreamless sleep.
The little town of Bethlehem does not lie still in deep or dreamless sleep.
I didn't go to sleep till 3 or 4. It was a dreamless sleep.
