a unit that quantifies the biological effectiveness of an absorbed dose of ionizing radiation, obtained by multiplying the absorbed dose by dimensionless factors that account for the kind of radiation, its energy, and the nature of the absorber: measured in Sievert or rem.
British Dictionary definitions for dose equivalent
a quantity that expresses the probability that exposure to ionizing radiation will cause biological effects. It is usually obtained by multiplying the dose by the quality factor of the radiation, but other factors may be considered. It is measured in sieverts (SI unit) or rems