From Pluralpedia, the collaborative plurality dictionary
renderspace (n., adj.)
Applies toheadspaces
CoinerFrost System

A renderspace is a headspace which persistently exists, but is not always visually present. Headmates, NPCs, and other phenomenon may continue to occur in a renderspace, but the renderspace and things within it only gain visual properties when directly observed, especially by the front.

The properties of a renderspace may be compared to the loading properties of some video games; textures and visual aspects are only loaded when within the frame of view, but entities and objects continue to exist and act outside of that frame of view. This behavior is where the prefix "render" is taken from.