megadeath

n. death of million people (military term usually referring to casualties of nuclear war)

This article is about Megadeath, not to be confused with Megadeth, an American thrash metal band. Megadeath (or megacorpse) is a term for one million deaths. It was coined in 1953 by RAND military strategist Herman Kahn and popularized in his 1960 book On Thermonuclear War. In Kahn's view, alternate scenarios in which the United States of America suffers 10 megadeaths instead of 100 should be weighed as "tragic but distinguishable outcomes." Though the term was created in order to discuss the likely consequences of conducting nuclear war, such a large number of deaths could also be associated with other weapons of mass destruction and extreme cases of democide.
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Noun
1. the death of a million people; "they calibrate the effects of atom bombs in megadeaths"
(hypernym) death, decease