I need some synonyms

[classicdrogn]

I see. Well, with more time to think about it, how about Transit (shape) and Tesseract? The latter is not technically accurate, but still commonly used in media. Discontinuity and Congruence (possibly +shape or point) as well, despite being roughly speaking antonyms.

Terminus or Coterminous (volume/shape)

There's also your Space Folds and Hyper- or Sub-space Windows, adding the name or initials of a mage, researcher, or engineer who discovered the theory and/or made it practically usable, and any number of variations on Dimension Door or Step/Slice/Slash/Tear/etc.

I recall one book that called it "Duckson's Dumper" having originally been intended as a way to dispose of trash without landfills. This gave earthlings an understandably bad reputation in wider society as it meant loads of garbage kept appearing until they managed to make contact back and tell that Earth to knock it off. I can't remember the title and Google doesn't find anything searching for the phrase, but it may have been by Somtow Sucharitkul/S. P. Somtow - I know I read it around the same time as I discovered Mallworld and a couple of others by him at the then-local used book shop, and at least in memory the style was similar. Obviously without more details it's probably better to avoid a direct use of that, but there are a few HP fics that have played with the idea of "what happens to Vanished items?" as well, so the theme is certainly available to work with to give you another direction to look for inspiration.

edit: There's also Dark, High, Low, or Elven Path, and The Place Between