REM

/rɛm/

/rɛm/

Other forms: REMS

REM is the stage of sleep when someone is dreaming and their eyes are moving behind their closed lids. If your dog's legs move and twitch like he's running in his sleep, he's in a REM state.

REM is an acronym of rapid eye movement. Scientists once believed that all dreaming happened during this phase of sleep, but they now know that it's possible to dream all night long, even when you're not in the REM stage. Still, it's when dreams are most obvious in your sleeping body, as your closed eyes move rapidly. If you sleep for seven or eight hours, you'll typically cycle through four periods of REM sleep.

Definitions of REM

1. noun

   a recurring sleep state during which dreaming occurs; a state of rapidly shifting eye movements during sleep
   synonyms: REM sleep, paradoxical sleep, rapid eye movement, rapid eye movement sleep

   type of:

   sleep, slumber

   a natural and periodic state of rest during which consciousness of the world is suspended
2. noun

   (Roentgen Equivalent Man) the dosage of ionizing radiation that will cause the same amount of injury to human tissue as 1 roentgen of X-rays
   type of:

   radioactivity unit

   a measure of radioactivity