英文字典中文字典51ZiDian.com

WordNet (r) 3.0 (2006) (WordNet)

REM
n 1: a recurring sleep state during which dreaming occurs; a
state of rapidly shifting eye movements during sleep [synonym:
{paradoxical sleep}, {rapid eye movement sleep}, {REM
sleep}, {rapid eye movement}, {REM}]
2: (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