Empty space or area (4)
I believe the answer is:
void
I believe this clue is a double definition.
'empty space' is the first definition.
(I've seen this in another clue)
'area' is the second definition.
(thesaurus)
(Other definitions for void that I've seen before include "Vacant; not valid" , "Blank, invalid" , "Empty space or not legally binding" , "Nullify" , "Null and invalid" .)