megadeath

/ˈmɛɡəˌdɛθ/
noun
  1. A unit equal to one million deaths, used especially in estimating the casualties of nuclear war.
    • The treaty aimed to reduce the risk of a conflict that would result in megadeaths.
    • The report calculated that a single nuclear bomb could cause one megadeath.
    • During the Cold War, strategists often discussed scenarios involving multiple megadeaths.