REM sleep: Meaning and Definition of

REM' sleep"

Pronunciation: [key]
— Physiol. Physiol.
  1. a recurrent period of sleep, typically totaling about two hours a night, during which most dreaming occurs as the eyes move under closed lids and the skeletal muscles are deeply relaxed. Also calledCf.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.