multimegaton

adjective

mul·​ti·​mega·​ton ˌməl-tē-ˈme-gə-ˌtən 

-ˌtī-

: being or producing an explosive force of many megatons

The United States tested a multimegaton H-bomb, and so the Soviet Union developed its own H-bomb, and schoolchildren from Minneapolis to Minsk cowered under their desks.

—Michael Nesset

Word History

First Known Use

1954, in the meaning defined above