Wife finds everything an obstacle (4)
I believe the answer is:
wall
'obstacle' is the definition.
'wife finds everything' is the wordplay.
'wife' becomes 'w' (abbreviation).
'finds' is a charade indicator (letters next to each other).
'everything' becomes 'all' (all things).
'w'+'all'='WALL'
'an' is the link.
(Other definitions for wall that I've seen before include "that may consist of many courses" , "Brick fence" , "Solid barrier" , "Side of building" , "Barrier, internal or external" .)