noun
megaton bomb
A nuclear weapon with an explosive yield measured in megatons of TNT.
冷戦時代にはメガトン爆弾の開発競争が激化した。
During the Cold War, the race to develop megaton bombs intensified.
Compound of メガトン (megaton) and 爆弾 (bomb). メガトン is a loanword from English 'megaton'.