Black duck after look finds summerhouse (6)
I believe the answer is:
gazebo
'summerhouse' is the definition.
(I know that summerhouse can be written as gazebo)
'black duck after look' is the wordplay.
'black' becomes 'b' (as in pencil classifications).
'duck' becomes 'o' (resembles zero - 'duck' in cricket).
'after' says to put letters next to each other.
'look' becomes 'gaze' (gaze is a kind of look).
'b'+'o'='bo'
'bo' after 'gaze' is 'GAZEBO'.
'finds' acts as a link.
(Other definitions for gazebo that I've seen before include "Summerhouse with a good view" , "Type of summerhouse" , "Garden sumer-house with wide view" , "Small garden building for shade and rest" , "Garden shelter" .)