Region; space (4)
I believe the answer is:
area
This clue is a double definition.
'region' is the first definition.
(area is a kind of region)
'space' is the second definition.
(I've seen this before)
(Other definitions for area that I've seen before include "topic" , "Extent of a 2-dimensional surface" , "Patch" , "Geographical region" , "Locality" .)