Definition of megabook in US English:

megabook

adjective

  • Of a library or bookshop: having many books.

noun

  • 1A best-selling book.

  • 2A book designed to be encyclopedic in its breadth.

Origin

1960s; earliest use found in Cambridge Review: a journal of university life and thought. From mega- + book.

Pronunciation

megabook

/ˈmɛɡəbʊk/