1. (

• paradoxical_sleep ,
• rapid_eye_movement_sleep ,
• REM_sleep ,
• rapid_eye_movement ,
• REM

) a recurring sleep state during which dreaming occurs; a state of rapidly shifting eye movements during sleep ;

2. (

• rem

) (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 ;