Definition of mega- in English:

mega-

combining form

  • 1Large.

    ‘megalith’
  • 2(in units of measurement) denoting a factor of one million (10⁶)

    ‘megahertz’
  • 3Computing
    Denoting a factor of 2²⁰.

Origin

From Greek megas ‘great’.

Pronunciation

mega-

/ˈmɛɡə/