Meaning

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

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

originClippings * (remaining time): Clipping of remaining. * (remark): Clipping of remark.

Etymology from Wiktionary, CC BY-SA 3.0