Micro-universe

The term "micro-universe" was used to describe the relative/infinite dimensions and even the dimensional transcendentalism of certain environments.

The Keeper described the virtual reality of the Matrix as being a micro-universe. (TV: The Ultimate Foe) The term was also used to describe the interior of a TARDIS, (PROSE: State of Change) and the Ringpullworld, which the Fifth Doctor also called a "dimension." (AUDIO: Ringpullworld)