The home designed by born monster (8)
I believe the answer is:
behemoth
'monster' is the definition.
('behemoth' can be a synonym of 'monster')
'the home designed by born' is the wordplay.
'designed' indicates an anagram (designed with the letters).
'by' means one lot of letters go next to another.
'born' becomes 'b'.
'the'+'home'='thehome'
'thehome' is an anagram of 'ehemoth'.
'ehemoth' put after 'b' is 'BEHEMOTH'.
(Other definitions for behemoth that I've seen before include "Giant" , "A huge beast in the Bible" , "Monstrous beast (Job)" , "Something abnormally large and powerful" , "Huge organisation" .)