What is the greek root word for other space?

There isn't a single Greek root word for "other space." The concept of "other space" is a modern one, and doesn't have a direct equivalent in ancient Greek.

However, you could piece together Greek words to express the idea, depending on the specific context. Here are some options:

* ἕτερος κόσμος (heteros kosmos): "other world" or "another cosmos." This emphasizes the idea of a different and separate space.

* ἄλλος τόπος (allos topos): "other place." This focuses more on the spatial aspect of "other space."

* ἐξωτερικός χώρος (exoterikos choros): "external space." This emphasizes the concept of space beyond our immediate surroundings.

Ultimately, the best Greek translation of "other space" will depend on the specific meaning and context you want to convey.