Definition of metagalaxy in US English:

metagalaxy

noun

Astronomy
  • The entire system of recognized galaxies; the entire material universe and the region of space it occupies. Now also (according to some theories): any of several such large-scale systems of galaxies.

Origin

1930s. From meta- + galaxy, after metagalactic.

Pronunciation

metagalaxy

/ˈmɛtəˌɡaləksi/