Force almost repaired wreckage (7)
I believe the answer is:
flotsam
'wreckage' is the definition.
(flotsam is a kind of wreckage)
'force almost repaired' is the wordplay.
'force' becomes 'F' (symbol used in Physics e.g. f=ma).
'repaired' is an anagram indicator.
'almost' anagrammed gives 'lotsam'.
'f'+'lotsam'='FLOTSAM'
(Other definitions for flotsam that I've seen before include "Shipwreck goods floating" , "Wreckage adrift at sea" , "Washed-up wreckage" , "Rubbish on sea" , "Detritus" .)