median lethal dose

noun
  1. the quantity of a lethal substance, as a poison or pathogen, or of ionizing radiation that will kill 50 percent of the organisms subjected to it in a specified time period. Symbol: LD50

Origin of median lethal dose

First recorded in 1945–50
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for median lethal dose

median lethal dose

mean lethal dose

noun
  1. the amount of a drug or other substance that, when administered to a group of experimental animals, will kill 50 per cent of the group in a specified time
  2. the amount of ionizing radiation that will kill 50 per cent of a population in a specified time
Abbreviation: LD 50
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012