Definition of megadecibel in English:

megadecibel

noun

figurative
  • A supposed unit of extreme loudness; an extremely loud sound, an extremely high degree of noise; frequently attributive.

Origin

1960s; earliest use found in Time. From mega- + decibel, as if from affix 2.

Pronunciation

megadecibel

/ˈmɛɡəˌdɛsɪb(ɛ)l/