Roentgen Equivalent Man. "A unit of biological dose of radiation... The number of rems of radiation is equal to the number of rads absorbed multiplied by the RBE of the given radiation (for a specified effect). The rem is also the unit of dose equivalent, which is equal to the product of the number of rads absorbed and the 'quality factor' of the radiation". (Glasstone, The Effects of Nuclear Weapons, 3rd Ed., 1977, Glossary, p. 638)