Definition of rem in English:



  • A unit of effective absorbed dose of ionizing radiation in human tissue, loosely equivalent to one roentgen of X-rays.

    • ‘The rem takes account of a ‘quality factor’, which for the more dangerous alpha particles is 10.’
    • ‘The modern international system of units includes the Gray, the Sievert, and the Becquerel (Bq); these replace the rad, rem, and Curie, respectively.’
    • ‘An area in which radiation levels could result in an individual receiving a dose equivalent in excess of 0.1 rem per hour.’
    • ‘According to Badhwar, the total increase in cosmonaut exposure was about 6 or 7 rem, a dose equivalent to 100 to 150 days of additional radiation exposure.’


1940s: acronym from roentgen equivalent man.