Fifth World

Short definition from Wiktionary

Proper noun

1. 1
   A world in a number of American mythologies: Synonym of Fifth Sun.
2. 2
   A world in a number of American mythologies: The world which will succeed the destruction of the present world, which is the Túwaquachi (also known as the Fourth World).
3. 3
   A world in a number of American mythologies: The present world, which the Navajo travelled through four worlds to reach.
4. 4
   Collectively, micronations which are advanced or developed; above the Sixth World and below.
5. 5
   Collectively, micronations which are advanced or developed; above the Sixth World and below: Collectively, all micronations.