Ship wreckage (7)
I believe the answer is:
flotsam
'ship wreckage' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for flotsam that I've seen before include "Wreck" , "Things going adrift" , "Rubbish on sea" , "Shipwreck goods floating" , "Vagrants" .)