Plane

In the terminology used in the Wongery (and by many choriologists, a plane is a continuous expanse of self-contained space, that is to say, that doesn't physically connect to any other such expanses. There's a little leeway given if the connections are very small; two large planes can be physically connected through a narrow wormhole and still be considered separate planes. This may seem to lead to ambiguity concerning where exactly the line is drawn, and just how big the connections can be between two planes before they have to be considered one, but in practice such borderline cases very seldom arise; for the most part, it's pretty clear what are and are not separate planes.

Generally, the unmodified word plane is reserved for relatively large expanses--hundreds of kilometers across, at the very least. Smaller self-contained spaces are called by other terms such as "pocket planes". Choriologists don't hold to this distinction, and technically any self-contained space can accurately be called a plane, but in common usage other terms are still used for particularly small planes.

One example of a plane is Tamamna, the universe in which the Sun and the Earth are located. (In general, all universes are planes, but not all planes are universes.)