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. : LD 5 0

median 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

Word History and Origins

Origin of median lethal dose¹

First recorded in 1945–50

Example Sentences

He must have taken enough roentgens of gamma and neutrons to reach or exceed the median-lethal dose.

From Project Gutenberg