I coined the term "Xenoserver" back in 1999, for a paper in IEEE HotOS proposing an architecture for allowing systems in core networks to safely accept and execute code from untrusted users (for a fee, of course!): https://www.cl.cam.ac.uk/research/srg/netos/papers/1999-hoto...
I was inspired by the word "xenos" (meaning both stranger and guest, or in combination a stranger who you invited into your home) rather than the word "xenia" for the general concept of hospitality extended to such a stranger [EDIT: since I wasn't familiar with the word "xenia"].
The Xenoserver project at Cambridge University developed this idea, and eventually focused around the hypervisor, which took on the name Xen.
