(Science: radiobiology) The conventional unit of dose equivalent. The dose equivalent in rem is numerically equal to the absorbed dose, D, in rad multiplied by the quality factor Q. 1 rem = 0.01 sievert. (See sievert, rad). Note: for most medical applications involving x-ray or gamma emitters, the numerical values of the absorbed dose in rad, dose equivalent in rem and exposure in R are roughly equivalent numerically.