It's not exactly what you'd call sleep, but it's an improvement.

Something quite unknown to us that is capable of inducing - let's call it artificial sleep.

Just before calling sleep, the consumer is interrupted and the producer is resumed.

It was time Annette went up to her for good; and there was a thing they called twilight sleep.

The stranger slept on-if his state could be called sleep as she dragged herself back and forth across the hut.

He had discovered an until then unknown state of consciousness, that he called "magnetic sleep".

I slept, if it may be called sleep, only for a moment.

It is an illusion of reality experienced during the temporary suspension of conscious thought which you call sleep.

It could not yet be called sleep.

It is a state that the humans call sleep.