Bogey fault west of Paddington? (7)
I believe the answer is:
bugbear
'bogey' is the definition.
(thesaurus)
'fault west of paddington?' is the wordplay.
'fault' becomes 'bug' (bug is a kind of fault).
'west of' means one lot of letters go next to another.
'paddington?' becomes 'bear' (Paddington Bear is an example).
'bug'+'bear'='BUGBEAR'
(Other definitions for bugbear that I've seen before include "Cause of annoyance, fear" , "Cause of great distress" , "Nasty goblin - cause of fear" , "Nuisance" , "It causes obsessive fear" .)