Simple home requires fences (4)
I believe the answer is:
mere
'simple' is the definition.
(I know that simple can be written as mere)
'home requires fences' is the wordplay.
'fences' says the answer is hidden in the clue (the solution is fenced in by the clue).
'MERE' can be found hidden inside 'home requires'.
(Other definitions for mere that I've seen before include "Without additions or modifications" , "Pond, only what is said" , "of no significance" , "Just an English lake" , "Pure; lake" .)