Rubbish celebrity practically pocketing shedloads (7)
I believe the answer is:
flotsam
'rubbish' is the definition.
(I've seen this before)
'celebrity practically pocketing shedloads' is the wordplay.
'celebrity' becomes 'fame' (synonyms).
'practically' means to remove the last letter.
'pocketing' is an insertion indicator.
'shedloads' becomes 'lots' (both can mean large amounts).
'fame' with its final letter taken away is 'fam'.
'fam' placed around 'lots' is 'FLOTSAM'.
(Other definitions for flotsam that I've seen before include "Wreckage adrift at sea" , "Detritus" , "Rubbish on sea" , "Things found floating from a ship" , "Wreck" .)