REM sleep

noun

: a stage of sleep during which you dream and your eyes make quick movements

Full Definition of REM SLEEP

: a state of sleep that recurs cyclically several times during a normal period of sleep and that is characterized especially by increased neuronal activity of the forebrain and midbrain, depressed muscle tone, dreaming, and rapid eye movements —called also paradoxical sleep, rapid eye movement sleep — compare slow-wave sleep

See REM sleep defined for English-language learners

First Known Use of REM SLEEP

1965

Medical Dictionary

REM sleep

noun

Medical Definition of REM SLEEP

: a state of sleep that recurs cyclically several times during a normal period of sleep and that is characterized by increased neuronal activity of the forebrain and midbrain, by depressed muscle tone, and especially in humans by dreaming, rapid eye movements, and vascular congestion of the sex organs—called also desynchronized sleep, paradoxical sleep, rapid eye movement sleep; compare slow-wave sleep