Wharf features disheartened piper (4)
I believe the answer is:
pier
'wharf' is the definition.
(I know that wharf can be written as pier)
'disheartened piper' is the wordplay.
'disheartened' says to hollow out the word (remove centre letters) (the middle or heart is removed).
'piper' with its middle removed is 'PIER'.
'features' is the link.
I am not very happy about this link. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for pier that I've seen before include "Seaside platform" , "Support member" , "such as you might see at the seaside" , "Structure extending seawards" , "Part of airport terminal; breakwater" .)