A collective group of universes, which are close together and a small part of the entire multiverse.
'The megaverse is a collective group of several universes (extremely hypermassive globular clusters of galaxies, in an infinite empty dark void, 'Chaos' ), which are close together and only make up a small part of the entire multiverse.'

(Note: megaverse isn't to be confused with multiverse. Please read my definition of multiverse for more information).
by DianaLuciusDeCollis July 6, 2022
A collective group of finite universes, which are close together and a small part of the multiverse.
'In the multiverse, there's not one megaverse, but many of them: Collective groups of finite universes (extremely hypermassive globular clusters of galaxies floating in an infinite empty dark void known as, 'Chaos'), which are close together and are only a small fraction of the entire multiverse.'

(Note: A megaverse isn't to be confused with the multiverse or multi-metaverse. Please read my definitions for these terms).
by DianaLuciusDeCollis July 5, 2022