Uncultivated land with space for retreat (4)
I believe the answer is:
moor
'uncultivated land' is the definition.
(a moor is wild land)
'space for retreat' is the wordplay.
'space' becomes 'room' (enough space or room to do something).
'for retreat' shows that the letters should be reversed in order (retreat can mean to go back).
'room' back-to-front is 'MOOR'.
'with' acts as a link.
(Other definitions for moor that I've seen before include "Heathland" , "Make fast a boat - open tract of rough ground" , "Desolate area" , "Ilkley or Bodmin" , "Secure boat with ropes" .)