Look behind outhouse initially for shelter in garden (6)
I believe the answer is:
gazebo
'shelter in garden' is the definition.
(structure erected in a garden)
'look behind outhouse initially' is the wordplay.
'look' becomes 'gaze' (gazing is a kind of looking).
'initially' suggests taking the first letters.
The initial letters of 'behind outhouse' is 'bo'.
'gaze'+'bo'='GAZEBO'
'for' is the link.
(Other definitions for gazebo that I've seen before include "Summer house with a wide view" , "Small garden building for shade and rest" , "Summerhouse with views" , "Garden shelter" , "Garden sumer-house with wide view" .)