Docking platform (4)
I believe the answer is:
pier
'docking platform' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for pier that I've seen before include "Landing-stage or promenade" , "'Dock, wharf (4)'" , "seaside building" , "Surviving antiquity" , "sight at the seaside" .)