Pocket universe
From Jenny Everywhere Wiki
Pocket universes were universes whose structure was smaller and simpler than full universes. They could often be artificial, spin-offs from larger universes created as refuges by their inhabitants.
One pocket universe, which the Faction of the Fooling Fish dubbed “Dimension Zeta-32-Orangepeel-Grbbrzkwlkglb”, was created as a haven by the survivors of a pandimensional war. It was heavily shielded by a sphere of energy, preventing easy entry into it from the Void or the Chronon Sea. (PROSE: The Winter Quests)
